Photoconductive member having amorphous layer containing oxygen

ABSTRACT

A photoconductive member, comprises a support for a photoconductive member and an amorphous layer which is constituted of silicon atoms as matrix containing at least one of hydrogen atom and halogen atom and exhibits photoconductivity, said amorphous layer having a layer region containing oxygen atoms in at least a part thereof, the content of the oxygen atoms in said layer region being distributed unevenly in the direction of the thickness of said layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a photoconductive member having sensitivity toelectromagnetic waves such as light. [herein used in a broad sense,including ultraviolet rays, visible light, infrared rays, X-rays andgamma-rays].

2. Description of the Prior Arts

Photoconductive materials, which constitute image forming members forelectrophotography in solid state image pick-up devices or in the fieldof image formation, or photo-conductive layers in manuscript readingdevices, are required to have a high sensitivity, a high SN ratio[Photocurrent (I_(p))/Dark current (I_(d))], spectral characteristicscorresponding to those of electromagnetic waves to be irradiated, a goodresponse to light, a desired dark resistance value as well as no harm tohuman bodies during usage. Further, in a solid state image pick-updevice, it is also required that the residual image should easily betreated within a predetermined time. In particular, in case of an imageforming member for electrophotography to be assembled in anelectrophotographic device to be used in an office as office apparatus,the aforesaid harmless characteristic is very important.

From the standpoint as mentioned above, amorphous silicon [hereinafterreferred to as a-Si] has recently attracted attention as aphotoconductive material. For example, German Laid-Open PatentPublication Nos. 2746967 and 2855718 disclose applications of a-Si foruse in image forming members for electrophotography, and U.K. Laid-OpenPatent Publication No. 2029642 an application of a-Si for use inphotoconverting reading device. However, the photoconductive membershaving photoconductive layers constituted of a-Si of prior art havevarious electrical, optical and photoconductive characteristics such asdark resistance value, photosensitivity and response to light as well asenvironmental characteristics in use such as weathering resistance andhumidity resistance, which should further be improved. Thus, in apractical solid state image pick-up device, reading device or an imageforming member for electrophotography, they cannot effectively be usedalso in view of their productivity and possibility of their massproduction.

For instance, when applied in an image forming member or a photographicdevice, residual potential is frequency observed to remain during usethereof. When such a photoconductive member is repeatedly used for along time, there will be caused various inconveniences such asaccumulation of fatigues by repeated uses or so called ghost phenomenonwherein residual images are formed.

Further, according to the experience by the present inventors from anumber of experiments, a-Si material constituting the photoconductivelayer of an image forming member for electrophotography, while it has anumber of advantages, as compared with Se, CdS, ZnO or organicphotoconductive materials such as PVCz or TNF of prior art, is alsofound to have several problems to be solved. Namely, when chargingtreatment is applied for formation of electrostatic images on thephotoconductive layer of an image forming member for electrophotographyhaving a photoconductive member constituted of a mono-layer of a-Siwhich has been endowed with characteristics for use in a solar batteryof prior art, dark decay is markedly rapid, whereby it is difficult toapply a conventional photographic method. This tendency is furtherpronounced under a humid atmosphere to such an extent in some cases thatno charge is retained at all before development.

Thus, it is required in designing of a photoconductive material to makeefforts to obtain desirable optical and photoconductive characteristicsalong with the improvement of a-Si materials per se and to make aphotoconductive member capable of obtaining stable image-quality withhigh sensitivity.

In view of the above points, the present invention contemplates theachievement obtained as a result of extensive studies madecomprehensively from the standpoints of applicability and utility ofa-Si as a photoconductive member for image forming members forelectrophotography, solid state image pick-up devices or readingdevices. It is now been found that a photoconductive member elaboratedto have a layer structure comprising an amorphous layer exhibitingphotoconductivity, which is constituted of so called hydrogenatedamorphous silicon, halogenated amorphous silicon or halogen-containinghydrogenated amorphous silicon which is an amorphous material containingat least one of hydrogen atom (H) and halogen atom (X) in a matrix ofsilicon [hereinafter referred to comprehensively as a-Si(H,X)], andprepared to have a specific composition as described hereinafter, is notonly usually useful but also has characteristics superior insubstantially all respects to those of the photoconductive members ofprior art, especially markedly excellent characteristics as aphotoconductive member for electrophotography with respect tophotosensitivity and stabilization of image quality. The presentinvention is based on such finding.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide aphotoconductive member having constantly stable electrical, optical andphotoconductive characteristics, which is an all-environment typesubstantially without limitations with respect to the environment underwhich it is used, being markedly excellent in light-resistant fatiguewithout deterioration after repeated uses and free entirely orsubstantially from residual potentials observed.

Another object of the present invention is to provide a photoconductivemember, having a high photosensitivity with a spectral sensitive regioncovering substantially all over the region of visible light, and havingalso a rapid response to light.

Still another object of the present invention is to provide aphotoconductive member, which is sufficiently capable of bearing chargesat the time of charging treatment for formation of electrostatic chargesto the extent such that a conventional electrophotographic method can beapplied when it is provided for use as an image forming member forelectrophotography, and which has excellent electrophotographiccharacteristics of which substantially no deterioration is observed evenunder a highly humid atmosphere.

Further, still another object of the present invention is to provide aphotoconductive member for electrophotography capable of providingeasily a high quality image which is high in density, clear in halftoneand high in definition.

According to the present invention, there is provided a photoconductivemember, comprising a support for a photoconductive member and anamorphous layer [a-Si(H,X)] which is constituted of silicon atoms asmatrix containing at least one of hydrogen atom (H) and halogen atom (X)and exhibits photoconductivity, said amorphous layer having a layerregion containing oxygen atoms in at least a part thereof, the contentof the oxygen atoms in said layer region being distributed unevenly inthe direction of the thickness of said layer.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing,

FIG. 1 shows a schematic sectional view of a preferred embodiment of thephotoconductive member according to the present invention;

FIGS. 2 through 12 schematic illustrations indicating distributionprofiles of oxygen atoms in the amorphous layers of preferredembodiments of the photoconductive members according to the presentinvention, respectively;

FIG. 13 a schematic sectional view of the layer structure of anotherpreferred embodiment of the photoconductive member according to thepresent invention; and

FIG. 14 a schematic flow chart for illustration of one example of devicefor preparation of the photoconductive member according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawing, the photoconductive members according tothe present invention are to be described in detail below.

FIG. 1 shows a schematic sectional view for illustration of a typicalexemplary constitution of the photoconductive member of this invention.

The photoconductive member 100 as shown in FIG. 1 comprises a support101 for photoconductive member, a barrier layer 102, which mayoptionally be provided on said support as an intermediate layer, and anamorphous layer 103 exhibiting photoconductivity, said amorphous layerhaving a layer region containing oxygen atoms in at least a partthereof, the content of oxygen atoms in said layer region beingdistributed unevenly in the direction of thickness of the layer.

The photoconductive member designed to have the layer structure asdescribed above has overcome all of the problems as mentioned above andexhibits excellent electrical, optical and photoconductivecharacteristics as well as good adaptability for environments duringusage.

In particular, when it is applied as an image forming member forelectrophotography, it has good charge bearing capacity during chargingtreatment without influence of residual potential on the imageformation, and its electrical properties are stable even in a high humidatmosphere. Moreover, it is highly sensitive and has a high SN ratio aswell as good performance of repeated uses, thus being capable of givingconstantly visible images of high quality with high density, clearhalftone and high resolution.

The support 101 may be either electroconductive or insulating. As theelectroconductive material, there may be mentioned metals such as NiCr,stainless steel, Al, Cr, Mo, Au, Nb, Ta, V, Ti, Pt, Pd, etc. or alloysthereof.

As insulating supports, there may conventionally be used films or sheetsof synthetic resins, including polyesters, polyethylene, polycarbonates,cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidenechloride, polystyrene, polyamides, etc., glasses, ceramics, papers andthe like. These insulating supports may suitably have at least onesurface subjected to electroconductive treatment, and it is desirable toprovide other layers on the side at which said electroconductivetreatment has been applied.

For example, electroconductive treatment of a glass can be effected byproviding a thin film of NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt,Pd, In₂ O₃, SnO₂, ITO(In₂ O₃ +SnO₂) thereon. Alternatively, a syntheticresin film such as polyester film can be subjected to theelectroconductive treatment on its surface by vapor deposition,electron-beam deposition or sputtering of a metal such as NiCr, Al, Ag,Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt, etc. or by laminatingtreatment with said metals. The support 101 may be shaped in any formsuch as cylinders, belts, plates or others, and its form may bedetermined as desired. For example, when the photoconductive member 100in FIG. 1 is to be used as an image forming member forelctrophotography, it may desirably formed into an endless belt or acylinder for use in continuous high speed copying. The support 101 mayhave a thickness, which is conveniently determined so that aphotoconductive member as desired may be formed. When thephotoconductive member is required to have a flexibility, the support ismade as thin as possible, so far as the function of a support can beexhibited. However, in such a case, the thickness is generally 10μ ormore from the points of fabrication and handling of the support as wellas its mechanical strength.

The barrier layer 102 has the function of barring effectively injectionof free carriers into the side of the amorphous layer 103 from the sideof the support 101 and permitting easily the photocarriers generated byirradiation of electromagnetic waves in the amorphous layer 103 andmigrating toward the support 101 to pass therethrough from the side ofthe amorphous layer 103 to the side of the support 101.

While the barrier layer 102 can be provided to give the function asdescribed above, it is not absolutely required in the present inventionto provide such a barrier layer 102 only if the function similar to thatof the barrier layer 102 can be exhibited sufficiently at the interfacebetween the support 101 and the amorphous layer 103 when the amorphouslayer 103 is provided directly on the support 101.

The barrier layer 102, which is formed so as to have the function asdescribed above exhibited to its full extent, may also desirably beformed so as to provide mechanical and electrical contactness andadhesion between the support 101 and the amorphous layer 103. As thematerial constituting the barrier layer 102, most materials can beadopted so long as they can give the various characteristics asmentioned above as desired.

Among such materials, those specifically mentioned as effectivematerials for the present invention may include amorphous materialscontaining at least one kind of atom selected from the group consistingof carbon (C), nitrogen (N) and oxygen (O), optionally together with atleast one of hydrogen atoms and halogen atom, in a matrix of siliconatoms [these are referred to comprehensively as a-[Si_(x) (C,N)_(1-x)]_(y) (H,X)_(1-y) (where 0<x<1, 0<y<1)]; electrically insulating metaloxides, electrically insulating organic compounds; or the like.

In the present invention, in case of the materials containing halogenatoms (X) among these constituting the above-mentioned barrier layer102, the halogen atom may preferably be F, Cl, Br or I, especially F orCl.

Typical examples of the amorphous materials as mentioned aboveeffectively used for constituting the barrier layer 102 may include, forexample, carbon type amorphous materials such as a-Si_(a) C_(1-a),a-(Si_(b) C_(1-b))_(c) H_(1-c), a-(Si_(d) C_(1-d))_(e) X_(1-e),a-(Si_(f) C_(1-f))_(g) (H+X)_(1-g) ; nitrogen type amorphous materialssuch as a-Si_(h) N_(1-h), a-(Si_(i) N_(1-i))_(j) H_(1-j), a-(Si_(k)N_(1-k))_(l) X_(1-l), a-(Si_(m) N_(1-m))_(n) (H+X)_(1-n) ; oxygen typeamorphous materials such as a-Si_(o) O_(1-o), a-(Si_(p) O_(1-p))_(q)H_(1-q), a-(Si_(r) O_(1-r))_(s) X_(1-s), a-(Si_(t) O_(1-t))_(u)(H+X)_(1-u) ; etc. Further, there may also be mentioned amorphousmaterials containing at least two or more kinds of atoms of C, N and Oas constituent atoms in the amorphous materials as set forth above(where 0<a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t,u<1).

These amorphous materials may suitably be selected depending on theproperties required for the barrier 102 by optimum design of the layerstructure and easiness in consecutive fabrication of the amorphous layer103 to be superposed on said barrier layer 102. In particular, fromstandpoint of properties, nitrogen type and oxygen type amorphousmaterials, especially oxygen type amorphous materials may preferably beselected.

The barrier layer 102 constituted of an amorphous materials as mentionedabove may be formed by the glow discharge method, the sputtering method,the ion implantation method, the ion plating method, the electron-beammethod or the like.

When the barrier layer 102 is formed according to the glow dischargemethod, the starting gases for formation of the aforesaid amorphousmaterial, which may be admixed, if necessary, with a diluting gas at adesired mixing ratio, are introduced into the chamber for vacuumdeposition, and the gas introduced is converted to a gas plasma byexcitation of glow discharge in said gas thereby to deposit thesubstance for forming the aforesaid amorphous material on the support101.

In the present invention, the substances effectively used as thestarting materials for formation of the barrier layer 102 constituted ofcarbon type amorphous materials may include silicon hydride gasesconstituted of Si and H atoms such as silanes, as exemplified by SiH₄,Si₂ H₆, Si₃ H₈, Si₄ H₁₀, etc., hydrocarbons constituted of C and H atomssuch as saturated hydrocarbons having 1 to 5 carbon atoms, ethylenichydrocarbons having 2 to 5 carbon atoms or acetylenic hydrocarbonshaving 2 to 4 carbons atoms. More specifically, typical examples aresaturated hydrocarbons such as methane (CH₄), ethane (C₂ H₆), propane(C₃ H₈), n-butane (n-C₄ H₁₀), pentane (C₅ H₁₂), and the like; ethylenichydrocarbons such as ethylene (C₂ H₄), propylene (C₃ H₆), butene-1 (C₄H₈), butene-2 (C₄ H₈), isobutylene (C₄ H₈), pentene (C₅ H₁₀), and thelike; and acetylenic hydrocarbons such as acetylene (C₂ H₂),methylacetylene (C₃ H₄), butyne (C₄ H₆), and the like.

Typical examples of the starting gas constituted of Si, C and H arealkyl silanes such as Si(CH₃)₄, Si(C₂ H₅)₄ and the like. In addition tothese starting gases, H₂ can of course be effectively used as thestarting gas for introduction of hydrogen atoms (H).

Among the starting gas for formation of the barrier layer 102constituted of carbon type amorphous materials containing halogen atoms,the starting materials for supplying halogen atoms may include singlesubstances of halogen, hydrogen halides, interhalogen compounds, siliconhalides, halogen-substituted silicon hydrides, etc. More specifically,there may be included single substances of halogen such as halogenicgases of fluorine, chlorine, bromine and iodine; hydrogen halides suchas HF, HI, HCl, HBr, etc.; interhalogen compounds such as BrF, ClF,ClF₃, ClF₅, BrF₅, IF₇, IF₅, ICl, IBr, etc.; silicon halides such asSiF₄, Si₂ F₆, SiCl₄, SiCl₃ Br, SiCl₂ Br₂, SiClBr₃, SiCl₃ I, SiBr₄, etc.;halogen-substituted silicon hydrides such as SiH₂ F₂, SiH₂ Cl₂, SiHCl₃,SiH₃ Cl, SiH₃ Br, SiH₂ Br₂, SiHBr₃.

In addition to those mentioned above, there are halogen-substitutedparaffinic hydrocarbons such as CCl₄, CHF₃, CH₂ F₂, CH₃ F, CH₃ Cl, CH₃Br, CH₃ I, C₂ H₅ Cl, etc.; fluorinated sulfur compounds such as SF₄,SF₆, etc.; alkyl silanes such as Si(CH₃)₄, Si(C₂ H₅)₄, etc.; andhalogen-containing alkyl silanes such as SiCl(CH₃)₃, SiCl₂ (CH₃)₂, SiCl₃CH₃, etc.

These substances for forming barrier layer may be selected and used asdesired in formation of the barrier layer so that silicon atoms, carbonatoms and, if necessary, halogen atoms and hydrogen atoms may beincorporated at a desirable composition ratio in the barrier layerformed.

For example, it is possible to form a barrier constituted of a-(Si_(f)C_(1-f))_(g) (X+H)_(1-g) by introducing Si(CH₃)₄, which can incorporatesilicon atoms, carbon atoms and hydrogen atoms easily and can form abarrier layer of desired properties, together with a compound forincorporation of halogen atoms such as SiHCl₃, SiCl₄, SiH₂ Cl₂, SiH₃ Cl,or the like at a suitable mixing ratio in a gaseous state into a devicesystem for formation of the barrier layer, followed by excitation ofglow discharge therein.

When the glow discharge method is adopted for constitution of thebarrier layer 102 with a nitrogen type amorphous material, a desiredmaterial may be selected from those mentioned above for formation of thebarrier layer and the starting material for supplying nitrogen atoms maybe used in addition thereto. Namely, as the starting materials which caneffectively be used as starting gases for supplying nitrogen atoms informing the barrier layer 102, there may be mentioned compoundsconstituted of N or N and H including gaseous or gasifiable nitrogen,nitrides and azides, as exemplified by nitrogen (N₂), ammonia (NH₃),hydrazine (H₂ NNH₂), hydrogen azide(HN₃), ammonium azide (NH₄ N₃), andso on. In addition, it is also possible to use a nitrogen halidecompound which can incorporate both nitrogen atoms and halogen atoms,such as nitrogen trifluoride (F₃ N), nitrogen tetrafluoride (F₄ N₂), andthe like.

When the glow discharge method is adopted for constituting the barrierlayer 102 with an oxygen type amorphous material, a desirable substanceis selected from those for formation of the barrier layer as mentionedabove and a starting material which can be a starting gas for supplyingoxygen atoms may be used in combination. That is, as the startingmaterials which can be effectively used as starting gases for supplyingoxygen atoms in formation of the barrier layer 102, there may bementioned oxygen (O₂), ozone (O₃), disiloxane (H₃ SiOSiH₃), trisiloxane(H₃ SiOSiH₂ OSiH₃), etc.

Other than these starting materials for formation of the barrier layer,there may also be mentioned, for example, carbon monoxide (CO), carbondioxide (CO₂), dinitrogen oxide (N₂ O), nitrogen monoxide (NO),dinitrogen trioxide (N₂ O₃), nitrogen dioxide (NO₂), dinitrogentetraoxide (N₂ O₄), dinitrogen pentoxide (N₂ O₅), nitrogen trioxide(NO₃), and the like.

As described above, when forming a barrier layer 102 according to theglow discharge method, the starting materials for formation of thebarrier layer are suitably selected from those mentioned above so thatthe barrier layer having the desired characteristics, which isconstituted of desired materials, can be formed. For example, when usingthe glow discharge method, there may be employed a single gas such asSi(CH₃)₄, SiCl₂ (CH₃)₂ and the like, or a gas mixture such as SiH₄ -N₂ Osystem, SiH₄ -O₂ (-Ar) system, SiH₄ -NO₂ system, SiH₄ -O₂ -N₂ system,SiCl₄ -NO-H₂ system, SiH₄ -NH₃ system, SiCl₄ -NH₄ system, SiH₄ -N₂system, SiH₄ -NH₃ -NO system, Si(CH₃)₄ -SiH₄ system, SiCl₂ (CH₃)₂ -SiH₄system, etc. as the starting material for formation of the barrier layer102.

Alternatively, the barrier layer 102 can be formed according to thesputtering method by using a single crystalline of polycrystalline Siwafer or a C wafer containing Si and C mixed therein as target, andeffecting sputtering of these in various atmospheres. For example, whenSi wafer is used as target, the starting gas for introduction of carbonatoms (C) and hydrogen atoms (H) or halogen atoms (X) which mayoptionally be diluted with a diluting gas, if desired, are introducedinto the deposition chamber for sputter to form a gas plasma of thesegases and effect sputtering of the aforesaid Si water. As other methods,by use of separate targets of Si and C, or one sheet of a mixture of Siand C, sputtering can be effected in a gas atmosphere containing atleast hydrogen atoms (H) or halogen atoms (X).

As the starting gases for incorporation of carbon atoms, hydrogen atomsor halogen atoms in the barrier layer formed, the aforesaid startinggases as shown in the glow discharge method may also be useful in thesputtering method.

For formation of a barrier layer 102 constituted of a nitrogen typeamorphous material according to the sputtering method, a singlecrystalline or polycrystalline Si wafer or Si₃ N₄ wafer or a wafercontaining Si and Si₃ N₄ mixed therein may be used as target andsputtering may be effected in various gas atmospheres.

For example, when Si wafer is used as target, a starting gas forintroduction of nitrogen atoms optionally together with a starting gasfor incorporation of hydrogen atoms and/or halogen atoms, for example H₂and N₂ or NH₃, which may be diluted with a diluting gas if desired, isintroduced into a deposition chamber for sputter, in which gas plasma ofthese gases is formed and the aforesaid Si wafer is subjected tosputtering.

Alternatively, with the use of Si and Si₃ N₄ as separate targets or withthe use of a target of one sheet of a mixture of Si and Si₃ N₄,sputtering may be effected in a diluted gas atmosphere as a gas forsputter or in a gas atmosphere containing at least one of H atoms and Xatoms.

As the starting gas for introduction of nitrogen atoms (N), there may beemployed those for introduction of nitrogen atoms (N) among the startingmaterials, as shown in examples for formation of the barrier layer bythe glow discharge method, as effective gases also in case ofsputtering.

For formation of a barrier layer 102 constituted of an oxygen typeamorphous material according to the sputtering method, a singlecrystalline or polycrystalline Si wafer or SiO₂ wafer or a wafercontaining Si and SiO₂ mixed therein may be used as target andsputtering may be effected in various gas atmospheres.

For example, when Si wafer is used as target, a starting gas forintroducton of oxygen atoms optionally together with a starting gas forincorporation of hydrogen atoms and/or halogen atoms, for example, SiH₄and O₂, or O₂, which may be diluted with a diluting gas if desired, isintroduced into a deposition chamber for sputter, in which gas plasma ofthese gases is formed and the aforesaid Si wafer is subjected tosputtering.

Alternatively, with the use of Si and SiO₂ as separate targets or withthe use of a target of one sheet of a mixture of Si and SiO₂, sputteringmay be effected in a diluted gas atmosphere as a gas for sputter or in agas atmosphere containing at least one of H atoms and X atoms.

As the starting gas for introduction of oxygen atoms (O), there may beemployed those for introduction of oxygen atoms (O) among the startingmaterials, as shown in examples for formation of the barrier layer bythe glow discharge method, as effective gases also in case ofsputtering.

As the diluting gas to be employed in forming the barrier layer 102according to the glow discharge method or the sputtering method, theremay included so called rare gases such as He, Ne, Ar, and the like assuitable ones.

When the barrier layer 102 is constituted of the amorphous material asdescribed above, it is formed carefully so that the characteristicsrequired may be given exactly as described.

That is, a substance constituted of Si and at least one of C, N and O,and optionally H or/and X can take various forms from crystalline toamorphous and electrical properties from conductive throughsemi-conductive to insulating and from photoconductive tonon-photoconductive depending on the preparation conditions. In thepresent invention, the preparation conditions are severely selected sothat there may be formed non-photoconductive amorphous materials atleast with respect to the light in so called visible region.

Since the function of the amorphous barrier layer 102 is to barinjection of free carriers from the side of the support 101 into theamorphous layer 103, while permitting easily the photocarriers generatedin the amorphous layer 103 to be migrated and passed therethrough to theside of the support 101, it is desirable that the above-mentionedamorphous materials are formed to exhibit electrically insulatingbehaviours at least in the visible light region.

The barrier layer 102 is formed also to have a mobility value withrespect to passing carriers to the extent that photocarriers generatedin the amorphous layer 103 can pass easily through the barrier layer102.

As another critical element in the conditions for preparation of thebarrier layer 102 from the amorphous material having the characteristicsas described above, there may be mentioned the support temperatureduring preparation thereof.

In other words, in forming a barrier layer 102 constituted of theaforesaid amorphous material on the surface of the support 101, thesupport temperature during the layer formation is an important factoraffecting the structure and characteristics of the layer formed. In thepresent invention, the support temperature during the layer formation isseverely controlled so that the aforesaid amorphous material having theintended characteristics may be prepared exactly as desired.

The support temperature during formation of the barrier layer 102, whichis selected conveniently within an optimum range depending on the methodemployed for formation of the barrier layer 102, is generally from 20°to 300° C., preferably 50° to 250° C. For formation of the barrier layer102, it is advantageous to adopt the glow discharge method or thesputtering method, since these methods can afford severe controlling ofthe atomic ratios constituting each layer or layer thickness withrelative ease as compared with other methods, when forming consecutivelythe amorphous layer 103 on the barrier layer 102 in the same system, andfurther a third layer formed on the amorphous layer 102, if desired. Incase of forming the barrier layer 102 according to these layer formingmethods, the discharging power and the gas pressure during layerformation may also be mentioned similarly to the support temperature asdescribed above, as important factors influencing the characteristics ofthe barrier layer to be prepared.

The discharging power conditions, for preparing the barrier layer 102having the characteristics to achieve the intended purpose effectivelywith good productivity, is generally 1 to 300 W, preferably 2 to 150 W.The gas pressure in the deposition chamber is generally 3×10⁻³ to 5Torr, preferably 8×10⁻³ to 0.5 Torr.

The contents of carbon atoms, nitrogen atoms, oxygen atoms, hydrogenatoms and halogen atoms in the barrier layer 102 are important factors,similarly to the conditions for preparation of the barrier layer 102,for forming the barrier layer provided with desired characteristics.

In forming the barrier 102 constituted of a-Si_(a) C_(1-a), the contentof carbon atoms may generally 60 to 90 atomic %, preferably 65 to 80atomic %, most preferably 70 to 75 atomic %, namely in terms ofrepresentation by the index a, 0.1 to 0.4, preferably 0.2 to 0.35, mostpreferably 0.25 to 0.3. In case of the constitution of a-(Si_(b)C_(1-b))_(c) H_(1-c), the content of carbon atoms is generally 30 to 90atomic %, preferably 40 to 90 atomic %, most preferably 50 to 80 atomic%, and the content of hydrogen atoms generally 1 to 40 atomic %,preferably 2 to 35 atomic %, most preferably 5 to 30 atomic %, namely interms of representations by the indexes b and c, b being generally 0.1to 0.5, preferably 0.1 to 0.35, most preferably 0.15 to 0.3, and c beinggenerally 0.60 to 0.99, preferably 0.65 to 0.98, most preferably 0.7 to0.95. In case of the constitution of a-(Si_(d) C_(1-d))_(e) X_(l-e) ora-(Si_(f) C_(1-f))_(g) (H+X)_(1-g), the content of carbon atoms isgenerally 40 to 90 atomic %, preferably 50 to 90 atomic %, mostpreferably 60 to 80 atomic %, the content of halogen atoms or the sum ofthe contents of halogen atoms and hydrogen atoms generally 1 to 20atomic %, preferably 1 to 18 atomic %, most preferably 2 to 15 atomic %,and the content of hydrogen atoms, when both halogen atoms and hydrogenatoms are contained, is generally 19 atomic % or less, preferably 13atomic % or less, namely in terms of representation by d, e, f and g, dand f are generally 0.1 to 0.47, preferably 0.1 to 0.35, most preferably0.15 to 0.3, e and g 0.8 to 0.99, preferably 0.85 to 0.99, mostpreferably 0.85 to 0.98.

When the barrier layer 102 is constituted of a nitrogen type amorphousmaterial, the content of nitrogen atoms in case of a-Si_(h) N_(1-h) isgenerally 43 to 60 atomic %, preferably 43 to 50 atomic %, namely interms of representation by h, generally 0.43 to 0.60, preferably 0.43 to0.50.

In case of the constitution of a-(Si_(i) N_(1-i))_(j) H_(1-j), thecontent of nitrogen atoms is generally 25 to 55 atomic %, preferably 35to 55 atomic %, and the content of hydrogen atoms generally 2 to 35atomic %, preferably 5 to 30 atomic %, namely in terms of representationby i and j, i being generally 0.43 to 0.6, preferably 0.43 to 0.5 and jgenerally 0.65 to 0.98, preferably 0.7 to 0.95. In case of theconstitution of a-(Si_(k) N_(1-k))_(l) X_(1-l) or a-(Si_(m) N_(1-m))_(n)(H+X)_(1-n), the content of nitrogen atoms is generally 30 to 60 atomic%, preferably 40 to 60 atomic %, the content of halogen atoms or the sumof contents of halogen atoms and hydrogen atoms generally 1 to 20 atomic%, preferably 2 to 15 atomic %, and the content of hydrogen atoms, whenboth halogen atoms and hydrogen atoms are contained, generally 19 atomic% or less, preferably 13 atomic % or less, namely in terms ofrepresentation by k, l, m and n, k and m being generally 0.43 to 0.60,preferably 0.43 to 0.49, and l and n generally 0.8 to 0.99, preferably0.85 to 0.98.

When the barrier layer 102 is constituted of an oxygen type amorphousmaterial, the content of oxygen atoms in the barrier layer 102constituted of a-Si_(o) O_(1-o) is generally 60 to 67 atomic %,preferably 63 to 67 atomic %, namely in terms of representation by ogenerally 0.33 to 0.40, preferably 0.33 to 0.37. In case of theconstitution of a-(Si_(p) O_(1-p))_(q) H_(1-q), the content of oxygenatoms in the barrier layer 102 is generally 39 to 66 atomic %,preferably 42 to 64 atomic %, and the content of hydrogen atomsgenerally 2 to 35 atomic %, preferably 5 to 30 atomic %, namely in termsof representation by p and q, p being generally 0.33 to 0.40, preferably0.33 to 0.37 and q generally 0.65 to 0.98, preferably 0.70 to 0.95. Whenthe barrier layer 102 is constituted of a-(Si_(r) O_(1-r))_(s) X_(1-s)or a-(Si_(t) O_(1-t))_(u) (H+X)_(1-u), the content of oxygen atoms inthe barrier layer 102 is generally 48 to 66 atomic %, preferably 51 to66 atomic %, the content of halogen atoms or the sum of contents ofhalogen atoms and hydrogen atoms, when hydrogen atoms further arecontained, generally 1 to 20 atomic %, preferably 2 to 15 atomic %, withthe content of hydrogen atoms, when both halogen atoms and hydrogenatoms are contained, being 19 atomic % or less, preferably 13 to atomic% or less. As represented in terms of r, s, t and u, r or t is generally0.33 to 0.40, preferably 0.33 to 0.37, and s or u generally 0.80 to0.99, preferably 0.85 to 0.98.

As the electrically insulating metal oxides for constituting the barrierlayer 102, there may preferably mentioned Al₂ O₃, BeO, CaO, Cr₂ O₃, P₂O₅, ZrO₂, HfO₂, GeO₂, Y₂ O₃, TiO₂, Ce₂ O₃, MgO, MgO.Al₂ O₃, SiO₂.MgO,etc. A mixture of two or more kinds of these compounds may also be usedto form the barrier layer 102.

The barrier layer 102 constituted of an electrically insulating metaloxide may be formed by the vacuum deposition method, the CVD (chemicalvapor deposition) method, the glow discharge decomposition method, thesputtering method, the ion implantation method, the ion plating method,the electron-beam method or the like.

For formation of the barrier layer 102 by the sputtering method, forexample, a wafer for formation of an barrier layer may be used as targetand subjected to sputtering in an atmosphere of various gases such asHe, Ne, Ar and the like.

When the electron-beam method is used, there is placed a startingmaterial for formation of the barrier layer in a boat for deposition,which may in turn be irradiated by an electron beam to effect vapordeposition of said material.

The barrier layer 102 is formed to exhibit electric insulating behavior,since the barrier layer 102 has the function of barring effectivelypenetration of carriers into the amorphous layer 103 from the side ofthe support 101 and permitting easily the photocarriers generated in theamorphous layer 103 and migrating toward the support 101 to passtherethrough from the side of the amorphous layer 103 to the side of thesupport 101.

The numerical range of the layer thickness of the barrier layer is animportant factor to achieve effectively the above-mentioned purpose. Inother words, if the layer thickness is too thin, the function of barringinjection of free carriers from the side of the support 101 into theamorphous layer 103 cannot sufficiently be fulfilled. On the other hand,if the thickness is too thick, the probability of the photo-carriersgenerated in the amorphous layer 103 to be passed to the side of thesupport 101 is very small. Thus, in any of the cases, the objects ofthis invention cannot effectively be achieved.

In view of the above points, a thickness of the barrier layer 102 isgenerally in the range of from 30 to 1000 Å, preferably from 50 to 600 Åfor achieving the objects of the present invention.

In the present invention, in order to achieve its objects effectively,the amorphous layer 103 provided on the support 101 is constituted ofa-Si(H, X) having the semiconductor characteristics as shown below, andfurther subjected to doping with oxygen atoms distributed in thedirection of the layer thickness in a fashion as hereinafter described:

1. p-type a-Si(H, X) . . . containing only acceptor; or containing bothdonor and acceptor with relatively higher concentration of acceptor(Na);

2. p⁻ -type a-Si(H, X) . . . in the type of 1. that containing acceptorwith lower acceptor concentration (Na) than 1. when containing onlyacceptor, or containing acceptor with relatively lower concentration ascompared with 1. when containing both acceptor and donor;

3. n-type a-Si(H, X) . . . containing only donor; or containing bothdonor and acceptor with relatively higher concentration of donor (Nd);

4. n⁻ -type a-Si(H, X) . . . in the type of 3., that containing doner atlower donor concentration (Nd) than 3., when containing only donor, orcontaining doner with relatively lower concentration as compared with3., when containing both acceptor and donor;

5. i-type a-Si(H, X) . . . Na≃Nd≃O or Na≃Nd.

In the present invention, typical examples of halogen atoms (X)contained in the amorphous layer 103 are fluorine, chlorine, bromine andiodine, and fluorine and chlorine are particularly preferred.

In the amorphous layer in the photoconductive member according to thepresent invention, there is provided a layer region containing oxygenatoms which are distributed evenly within a plane substantially parallelto the surface of the support but unevenly in the direction of layerthickness. According to a preferred embodiment, in addition to thisspecific feature, oxygen atoms are more enriched on the side of thesurface opposite to the support (i.e. the side of the free surface 104in FIG. 1), so that the maximum value C_(max) of its distributioncontent may be located at the aforesaid surface or in the vicinitythereof.

In FIGS. 2 through 5, there are shown typical examples of distributionsof oxygen atoms in the layer thickness direction of amorphous layercontained in the amorphous layer of a photoconductive member having suchoxygen atom content distribution. In FIGS. 2 through 5, the axis ofordinate shows the layer thickness t of the amorphous layer 103, t₀indicating the positions of the interface (lower surface) between theamorphous layer 103 and other material such as the support 101, thebarrier layer 102, and the like, and t_(s) the position of the interface(upper surface) (the same position as the free surface 104 in FIG. 1) ofthe amorphous layer 103 in the side of the free surface 104, wherein thelayer thinkness t increases from t₀ toward t_(s), while the axis ofabscissa shows the distribution content of oxygen atoms, C, at anyposition in the layer thickness direction in the amorphous layer 103,wherein the increase of distribution content is indicated in thedirection of the arrowhead and C_(max) indicates the maximumdistribution content of oxygen atoms at a certain position in thedirection of the thickness layer of the amorphous layer 103.

In the embodiment as shown in FIG. 2, the content of oxygen atomscontained in the amorphous layer 103 is distributed in said layer 103,in such a way that the content of oxygen atoms is monotonicallycontinuously increased from the lower surface position t₀ toward theupper surface position t_(s) until reaching the maximum distributionamount C_(max) at the position t₁, and thereafter, in the interval tothe surface position t_(s), the value C_(max) is maintained withoutchange in the distribution content, C.

When the photoconductive member 100 prepared has an amorphous layer 103having a free surface 104 as shown in FIG. 1, it is possible to increasethe content of oxygen atoms in the vicinity of the upper surfaceposition t_(s) by far greater than in other regions thereby to impartimproved charge bearing capacity to the free surface 104. In this case,such a layer region functions as a kind of so called barrier layer.

Thus, an upper barrier layer can be formed in the amorphous layer 103 byenriching extremely the content of oxygen atoms in the vicinity of thefree surface 104 of the amorphous layer 103 as compared with other layerregions. Alternatively, it is also possible to form an upper layer onthe surface of the amorphous layer 103 by use of materials having thesame characteristics as those of materials constituting the barrierlayer 102. The upper layer in this case may suitably be 30 Å to 5μ,preferably 50 Å to 2μ.

In the embodiment as shown in FIG. 3, in the layer region at the lowerpart between t₀ and t₂, there is contained no or less than detectablelimit of oxygen atom. From the position t₂ to t₃, the distributioncontent of oxygen atoms is increased monotonically as the first-orderfunction or approximately the first-order function, until it reaches themaximum distribution amount C_(max) at the position t₃. In the layerregion between t₃ and t_(s), oxygen atoms are contained uniformly in themaximum distribution content of C_(max).

Thus, in FIG. 3, the drawing is depicted as if no oxygen were containedat all in the interval between t₀ and t₂. This is because an amount ofoxygen atoms, if any, less than the detectable limit is dealt withsimilarly as no oxygen content.

Accordingly, in the present invention, the layer region indicated asoxygen content of 0 (for example, the layer region between t₀ and t₂ inFIG. 3) contains no oxygen atom at all or contains oxygen atoms only inan amount of less than the detectable limit. The detectable limit ofoxygen atoms at our present level of technology is 200 atomic ppm basedon silicon atoms.

In the embodiment as shown in FIG. 4, at the lower layer region (betweent₀ and t₄) in the amorphous layer 103, oxygen atoms are containeduniformly and evenly with its distribution content C being constantlyC₁, while in the upper layer region (between t₄ and t_(s)), oxygen atomsare distributed uniformly and evenly at the maximum distribution contentC_(max), thus providing incontinuously different distribution contents Cin lower and upper layer regions, respectively.

In the embodiment as shown in FIG. 5, oxygen atoms are contained at aconstant distribution content C₂ from the lower surface position t₀ tothe position t₅ in the amorphous layer 103, and the distribution contentof oxygen atoms is gradually increased from the position t₅ to theposition t₆, from which the distribution content of oxygen atoms isabruptly increased to the upper surface position t_(s), at which itreaches the maximum distribution content C_(max).

As described above, as a preferred embodiment of the photoconductivemember according to the present invention, it is desirable that oxygenatoms are contained in the amorphous layer 103 so that the oxygen atomsmay be distributed with distribution contents increasingly as nearer tothe upper surface position t_(s), in order to obtain a highphotosensitization and stable image characteristics.

In case of such distributions as shown in the embodiments in FIGS. 2through 5, wherein the oxygen atoms contained in the amorphous layer 103are distributed in the layer thickness direction with more enrichment onthe side opposite to the support 101, the total content of oxygen atomsC_(t) contained in the whole layer region is generally 0.05 to 30 atomic% based on silicon atoms, and the maximum distribution content C_(max)at the surface or in the vicinity of said surface opposite to thesupport 101 in said layer region is generally 0.3 to 67 atomic %,preferably 0.5 to 67 atomic %, most preferably 1.0 to 67 atomic %.

In the preferred embodiments of the photoconductive members of thisinvention are shown in FIG. 2 through FIG. 5, the intended object of thepresent invention can be effectively accomplished by adding oxygen atomsinto the amorphous layer 103 according to a desired distributionfunction so that the oxygen atoms contained in the amorphous layer 103may be distributed unevenly in the layer thickness direction of theamorphous layer 103, and while having the maximum distribution contentC_(max) at the upper surface position t_(s) or in the vicinity of t_(s),the distribution content being decreased from the upper surface positiont_(s) toward the lower surface position t₀. Further, the total contentof oxygen atoms in the whole amorphous layer is also important toaccomplish the objects of the present invention.

The total amount of oxygen atoms contained in the amorphous layer isgenerally within the range as specified above, but it is preferably 0.05to 20 atomic % relative to silicon atoms, most preferably 0.05 to 10atomic %.

In FIGS. 6 through 12, there is shown another preferred embodiment ofthe photoconductive member of this invention, having at least a layerregion, in which oxygen atoms contained in the amorphous layer 103 aresubstantially uniformly distributed in planes approximately parallel tothe surface of the support but distributed unevenly in the thicknessdirection of the layer, the oxygen atoms being distributed more enrichedon the side of the surface at which the support 101 is provided than inthe central portion of said layer region.

In the embodiment as shown in FIGS. 6 through 12, as distinguished fromthe embodiment as shown in FIGS. 2 through 5, the amorphous layer 103has at least a layer region, having the peak of distribution of oxygenatoms at the surface on the side at which the support 101 is provided orin the vicinity of said surface.

The meanings of the ordinate and abscissa axes in FIGS. 6 through 12 arethe same as in FIGS. 2 through 5, and the oxygen content indicated as 0means that the content of oxygen atoms is substantially 0, as describedpreviously with respect to FIGS. 2 through 5. And, the fact that thecontent of oxygen atoms is substantially 0 means that the amount ofoxygen atoms in the portion of the layer region is less than thedetectable limit as described above, thus including the case whereinoxygen atoms are actually contained in an amount less than thedetectable limit.

In the embodiment as shown in FIG. 6, the content of oxygen atoms in theamorphous layer 103 is distributed through said layer 103 such that thedistribution content from the lower surface position t₀ to the positiont₁ is constantly C₁, and the distribution content is decreased as afirst-order function from the distribution content C₂ from the positiont₁ to the upper surface position t_(s), until the content of oxygenatoms become substantially 0 on reaching the upper surface positiont_(s).

In the embodiment of FIG. 6, by increasing extremely the distributioncontent C between the layer thickness positions t₀ and t₁, the amorphouslayer 103 can be sufficiently endowed with the function of a barrierlayer at its lower surface layer region.

In the embodiment as shown in FIG. 7, the distribution of oxygen atomscontained in the amorphous layer 103 is such that the distributioncontent C₁ is constant from the lower surface position t₀ to theposition t₁, and the distribution content is gradually decreased with agentle curve from the position t₁ toward the upper surface positiont_(s).

In the embodiment as shown in FIG. 8, the distribution content isconstantly C₁ from t₀ to t₁, decreased as a first-order function from t₁to t₂ and again becomes constant at C₂ from t₂ to t_(s). In thisembodiment, the upper surface layer region of the amorphous layer 103can have sufficiently function of a barrier layer by incorporatingoxygen atoms in an amount enough to give a distribution content C₂ inthe upper surface layer region (the portion between t₂ and t_(s) in FIG.8) which can exhibit a barrier layer function.

Alternatively, it is also possible in case of the embodiment as shown inFIG. 8 to increase the distribution contents C of oxygen atoms at bothsurface sides of the amorphous layer 103 by far greater than that in theinternal portion, thereby permitting the both surface layer regions tofulfill the functions of barrier layers.

In the embodiment as shown in FIG. 9, the distribution profile of oxygenatoms between t₀ and t₂ is similar to that as shown in FIG. 7, but thedistribution content is abruptly increased incontinuously between t₂ andt_(s) to have a value of C₂, thus giving a different distributionprofile as a whole.

In the embodiment as shown in FIG. 10, the distribution profile issimilar to that as shown in FIG. 7 between t₀ and t₃, but there isformed a layer region with oxygen content of substantially zero betweent₃ and t₂, while a large amount of oxygen atoms are contained between t₂and t_(s) to provide a distribution content of C₂.

In the embodiment as shown in FIG. 11, the distribution content isconstantly C₁ between t₀ and t₁, decreased from the distribution contentC₃ to C₄ as a first-order function between t₁ and t₂ from the side oft₁, and again increased between t₂ and t_(s) up to a constant value C₂.

In the embodiment as shown in FIG. 12, the distribution content isconstantly C₁ between t₀ and t₁, and also there is formed a distributionprofile with a constant distribution content of C₂ between t₂ and t_(s),whle the distribution content gradually decreasing between t₂ and t₁from the t₁ side toward the central portion of the layer and againgradually increasing from said central portion to t₂, at which thedistribution content reaches the value of C₄.

As described above, in the embodiment as shown in FIGS. 6 through 12,there is provided a layer region having a peak of distribution contenton the surface of the amorphous layer 103 on the side of the support 102or in the vicinity of said surface, where oxygen atoms are more enrichedthan in the central portion of said amorphous layer 103. Moreover, ifnecessary, it is also possible to provide a layer region having morecontent of oxygen atoms than that in the central portion of theamorphous layer 103 also in the surface region of the amorphous layer103 being the opposite side to the support. Further, there may also beformed a layer region extremely enriched in content of oxygen atoms atthe lower surface or in the vicinity of said surface so that thefunction of a barrier layer may sufficiently be exhibited.

In the embodiments as shown in FIGS. 6 through 12, the peak valueC_(max) of the distribution content of oxygen atoms contained in theamorphous layer 103 in the layer thickness may generally range from 0.3to 67 atomic % to achieve effectively the objects of this invention,preferably from 0.5 to 67 atomic %, most preferably 1.0 to 67 atomic %.

In the photoconductive member according to the present invention, incase of the embodiments as shown in FIGS. 6 through 12, the oxygen atomsare contained in the amorphous layer 103 with an uneven distribution ofits content in the layer thickness direction of said amorphous layer103, assuming a distribution profile such that its distribution contentis decreased from the vicinity of the lower surface layer region towardthe central portion of said amorphous layer 103. However, the totalcontent of oxygen atoms contained in the amorphous layer 103 is alsoanother critical factor to achieve the objects of the present invention.

In the present invention, the total content of oxygen atoms in theamorphous layer 103 is generally 0.05 to 30 atomic % based on siliconatoms, preferably 0.05 to 20 atomic %, most preferably 0.05 to 10 atomic%.

FIG. 13 shows a schematic sectional view of still another preferredembodiment of the photoconductive member according to the presentinvention.

The photoconductive member 1300 as shown in FIG. 13, similarly to thatdescribed with reference to FIG. 1, comprises a support 1301 for thephotoconductive member, a barrier layer 1302 optionally provided on said1301, and an amorphous layer 1303, said amorphous layer 1303 containingoxygen atoms which are distributed substantially equally within planessubstantially parallel to the surface of said support 1301 but unevenlyin the thickness direction of said layer, with different distributionsin respective portions of the layer regions 1304, 1305 and 1306. Thatis, the amorphous layer 1303 is constituted of a lower layer region 1304in which oxygen atoms are distributed in the layer directionsubstantially uniformly with a distribution content of C₁, an upperlayer 1306 in which oxygen atoms are distributed in the layer thicknessdirection substantially uniformly with a distribution content of C₂, andan intermediate layer region 1305, sandwitched between both of theselayer regions, in which oxygen atoms are distributed in the layerthickness direction substantially uniformly with a distribution contentof C₃.

In the embodiment as shown in FIG. 13, the values of distributioncontent C₁, C₂ and C₃ of oxygen atoms in respective layer can bevariable as desired within the relationship C₃ <C₁, C₂. But in order toachieve the objects of the present invention more effectively, the upperlimit of the distribution content C₁ or C₂ is generally 66 atomic % orlower, preferably, 64 atomic % or lower, most preferably 51 atomic % orlower, its lower limit being generally 11 atomic % or higher, preferably15 atomic % or higher, most preferably 20 atomic % or higher. As for thevalue of the distribution amount C₃, its upper limit may generally 10atomic % or lower, preferably 5 atomic %, most preferably 2 atomic %,while the lower limit generally 0.01 atomic % or higher, preferably 0.02atomic % or higher, most preferably 0.03 atomic % or higher.

The total content of oxygen atoms in the amorphous layer 1303 may begenerally in the range from 0.05 to 30 atomic % based on silicon atoms,preferably from 0.05 to 20 atomic %, most preferably from 0.05 to 10atomic %.

The barrier layer 1302 is not necessarily required to be provided in thepresent invention, as described above with reference to FIG. 1, if thesame function as the barrier layer 1302 as described above can besufficiently exhibited at the interface formed between the support 1301and the amorphous layer 1303 when said amorphous layer is provideddirectly on said support 1301.

Further, by incorporating a sufficient quantity of oxygen atoms asdesired in the surface layer region in the amorphous layer 1303 on theside of the support 1301, a part of the layer region of the amorphouslayer 1303 can be endowed with the same function as the barrier layer1302, whereby the barrier layer 1302 can also be dispensed with. When apart of layer region of the amorphous layer 1303 is loaded with thefunction of a barrier layer, the content of oxygen atoms necessary forthe layer region exhibiting such a function is generally 39 to 69 atomic% based on silicon atoms, preferably 42 to 66 atomic %, most preferably48 to 66 atomic %.

In the present invention, formation of an amorphous layer constitutedessentially of a-Si (H, X) may be conducted according to the vacuumdeposition method utilizing discharging phenomenon, such as glowdischarge method, sputtering method or ion-plating method. For example,for formation of the amorphous layer according to the glow dischargemethod, a starting gas for incorporation of hydrogen atoms and/orhalogen atoms is introduced together with a starting gas for supplyingsilicon atoms (Si), capable of supplying silicon atoms (Si), into thedeposition chamber, wherein glow discharge is generated thereby to forma layer constituted of a-Si (H, X) on the surface of the given supportplaced previously on the predetermined position. For incorporation ofoxygen atoms (O) into the amorphous layer to be formed, a starting gasfor incorporation of oxygen atoms may be introduced into said depositionchamber at the time of forming said amorphous layer.

When it is to be formed according to the sputtering method, a startinggas for incorporation of hydrogen atoms and/or halogen atoms may beintroduced into the chamber for sputtering, when effecting sputteringupon the target formed of Si in an atmosphere of an inert gas such asAr, He or a gas mixture based on these gases.

As the method for incorporating oxygen atoms into the amorphous layer, astarting gas for incorporating oxygen atoms may be introduced into saiddeposition chamber at the time of layer formation with the growth of thelayer, or alternatively at the time of layer formation the target forincorporation of oxygen atoms previously provided in the depositionchamber may be subjected to sputtering.

The starting gas for supplying Si to be used in forming the amorphouslayer according to the present invention may include gaseous orgasifiable silicon hydrides (silanes) such as SiH₄, Si₂ H₆, Si₃ H₈, Si₄H₁₀, and the like as effective materials. In particular, SiH₄ and Si₂ H₆are preferred with respect to easy handling during layer formation andefficiency for supplying Si.

As the effective starting gas for incorporation of halogen atoms to beused in forming the amorphous layer according to the present invention,there may be mentioned a number of halogen compounds such as halogengases, halides, interhalogen compounds and silane derivativessubstituted with halogens which are gaseous or gasfiable.

Alternatively, it is also effective in the present invention to usegaseous or gasifiable silicon compounds containing halogen atoms, whichare constituted of both silicon atoms (Si) and halogen atoms (X).

Typical examples of halogen compounds preferably used in the presentinvention may include halogen gases such as of fluorine, chlorine,bromine or iodine and interhalogen compounds such as BrF, ClF, ClF₃,BrF₅, BrF₃, IF₇, IF₅, ICl, IBr, etc.

As the silicon compound containing halogen atoms, silicon halides suchas SiF₄, Si₂ F₆, SiCl₄, SiBr₄, or the like are preferred.

When the specific photoconductive member of this invention is formedaccording to the glow discharge method by use of a silicon compoundcontaining halogen atoms, it is possible to form an amorphous layer ofa-Si:X on the support without use of a silicon hydride gas as thestarting gas capable of supplying Si.

The basic procedure for forming the amorphous layer containing halogenatoms according to the glow discharge method comprises introducing astarting gas for supplying Si, namely a silicon halide gas and a gassuch as Ar, H₂, He, etc. at a predetermined ratio in a suitable gas flowquantity into the deposition chamber for formation of the amorphouslayer, followed by excitation of glow discharge to form a plasmaatomosphere of these gases, thereby forming an amorphous layer on apredetermined support. For the purpose of incorporating hydrogen atoms,it is also possible to form an amorphous layer by mixing a gas of asilicon compound containing hydrogen atoms at a suitable ratio withthese gases.

Each of the gases for introduction of respective atoms may be either asingle species or a mixture of plural species at a predetermined ratio.For formation of an amorphous layer of a-Si (H, X) by the reactionsputtering method or the ion-plating method, a target of Si is used andsputtering is effected thereon in a suitable gas plasma atmosphere incase of the sputtering method. Alternatively, in case of ion-platingmethod, a polycrystalline or single crystalline silicon is placed asvaporization source in a vapor deposition boat, and the siliconvaporization source is vaporized by heating according to resistanceheating method or electron beam method (EB method) thereby to permitvaporized flying substances to pass through a suitable gas plasmaatmosphere.

During this procedure, in either of the sputtering method or theion-plating method, for incorporation of halogen atoms into the layerformed, a gas of a halogen compound as mentioned above or a siliconcompound containing halogen at mentioned above may be introduced intothe deposition chamber to form a plasma atmosphere of said gas therein.

When incorporating hydrogen atoms, a starting gas for incorporation ofhydrogen atoms such as H₂ or silanes as mentioned above may beintroduced into a deposition chamber for sputtering, wherein a plasmaatmosphere of said gas may be formed.

The oxygen atoms contained in the amorphous layer formed with a desireddistribution profile in the direction of the layer thickness may beintroduced in the amorphous layer by introducing a starting gas forintroducing oxygen atoms at the time of layer formation as matching withgrowth of the layer according to the predetermined flow amount into thedeposition chamber for formation of said layer, with the amorphous layeris formed according to the glow discharge method, ion-plating method orreaction sputtering method.

For formation of the amorphous layer according to the sputtering method,a target for introduction of oxygen atoms may be provided in theaforesaid deposition chamber, and sputtering may be effected on saidtarget as matching with the growth of the layer.

In the present invention, as the starting gases for introduction ofoxygen atoms effectively used, there may be mentioned oxygen (O₂), ozone(O₃) and lower siloxanes constituted of Si, O and H such as disiloxaneH₃ SiOSiH₃, trisiloxane H₃ SiOSiH₂ OSiH₃ or the like. As the materialfor formation of a target for introduction of oxygen atoms, SiO₂ and SiOcan effectively used in the present invention.

In the present invention, as a starting gas for incorporation of halogenatoms to be used in forming the amorphous layer, there may effectivelybe used halogen compounds or halogen-containing silicon compounds asmentioned above. In addition to these, it is also possible to use agaseous or gasifiable halide containing hydrogen atom as one of theconstituents, including hydrogen halides such as HF, HCl, HBr, HI, etc.,halogen-substituted silicon hydrides such as SiH₂ F₂, SiH₂ Cl₂, SiHCl₃,SiH₂ Br₂, SiHBr₃, etc., as effective starting material for formation ofthe amorphous layer.

These halides containing hydrogen atoms may preferably be used asstarting materials for incorporation of halogen atoms, since hydrogenatoms, which are very effective for controlling electrical orphotoelectric properties, can be introduced simultaneously withintroduction of halogen atoms.

Other than the method as described above, hydrogen atoms may also beintroduced structurally into the amorphous layer by exciting dischargingin the deposition chamber in the co-presence of H₂ or silanes gas suchas SiH₄, Si₂ H₆, Si₃ H₈, Si₄ H₁₀, and the like with silicon compounds asa source for supplying Si.

For example, in case of the reaction sputtering method, using Si target,a gas for incorporation of halogen atoms and H₂ gas, optionally togetherwith an inert gas such as He, Ar, and the like are introduced into thedeposition chamber to form a plasma atmosphere therein, followed bysputtering of said Si target, whereby there can be obtained an amorphouslayer essentially constituted of a-Si (H, X) having desiredcharacteristics.

Furthermore, a gas such as B₂ H₆, PH₃, PF₃, and the like can be alsointroduced with the gases as mentioned above to thereby effect alsodoping of impurities.

The amount of hydrogen atoms (H) or halogen atoms (X) contained in theamorphous layer of the amorphous layer of the photoconductive memberaccording to the present invention, or total amount of both of theseatoms, may generally 1 to 40 atomic %, preferably 5 to 30 atomic %.

The content of H and /or X incorporated in the amorphous layer can becontrolled by controlling, for example, the temperature of thedeposition support and/or the amounts of the starting materials used forincorporation of H or X introduced into the deposition chamber,discharging power, etc.

In order to make the amorphous layer n-type, p-type or i-type, either orboth of n-type and p-type impurities which control the electricconduction type can be added into the layer in a controlled amountduring formation of the layer by the glow discharge method or thereaction sputtering method.

As the impurity to be added into the amorphous layer to make it inclinedfor i-type or p-type, there may be mentioned preferably an element inthe group III A of the periodic table, for example, B, Al, Ga, In, Tl,etc.

On the other hand, for making the layer inclined for n-type, there maypreferably be used an element in the group V A of the periodic table,such as N, P, As, Sb, Bi, etc.

The amount of the impurity to be added into the amorphous layer in thepresent invention, in order to have a desired conduction type, may be inthe range of 3×10⁻² atomic % or less in case of an impurity in the groupIII A of the periodic table, and 5×10⁻³ atomic % or less in case of animpurity in the group V A of the periodic table.

The layer thickness of the amorphous layer, which may suitably bedetermined as desired so that the photocarriers generated in theamorphous layer may be transported with good efficiency, is generally 3to 100μ, preferably 5 to 50μ.

EXAMPLE 1

Using a device as shown in FIG. 14 placed in a clean room which had beencompletely shielded, an image forming member for electrophotography wasprepared according to the following procedures.

A molybdenum plate (substrate) 1409 of 10 cm square having a thicknessof 0.5 mm, which surface had been cleaned, was fixed firmly on a fixingmember 1403 disposed at a predetermined position in a glow dischargedeposition chamber 1401. The substrate 1409 was heated by a heater 1408within the fixing member 1403 with a precision of ±0.5° C. Thetemperature was measured directly at the backside of the substrate by analumel-chromel thermocouple. Then, after confirming that all the valvesin the system were closed, the main valve 1410 was fully opened, andevacuation of the chamber 1401 was effected to about 5×10⁻⁶ Torr.Thereafter, the input voltage for the heater 1408 was elevated byvarying the input voltage while detecting the substrate temperatureuntil the temperature was stabilized constantly at 250° C.

Then, the auxiliary valves 1441-1, 1441-2, 1441-3 subsequently theoutflow valves 1426, 1427, 1429 and the inflow valves 1421, 1422, 1424were opened fully to effect degassing sufficiently in the mass flowcontrollers 1416, 1417, 1419 to vacuo. After closing the auxiliaryvalves 1441-1, 1441-2, 1441-3 and the valves 1426, 1427, 1429, 1421,1422, 1424, the valve 1431 of the bomb 1411 containing SiH₄ gas (purity:99.999%) diluted with H₂ to 10 vol. % [hereinafter referred to as SiH₄(10)/H₂ ] and the valve 1432 of the bomb 1412 containing O₂ gas (purity:99.999%) diluted with He to 0.1 vol. % [hereinafter referred to as O₂(0.1)/He] were respectively opened to adjust the pressures at the outletpressure gages 1436 and 1437, respectively, at 1 kg/cm², whereupon theinflow valves 1421 and 1422 were gradually opened to introduce SiH₄(10)/H₂ gas and O₂ (0.1)/He gas into the mass flow controllers 1416 and1417, respectively. Subsequently, the outflow valves 1426 and 1427 weregradually opened, followed by opening of the auxiliary valves 1441-1,1441-2. The mass flow controllers 1416 and 1417 were adjusted thereby sothat the gas flow amount ratio of SiH₄ (10)/H₂ gas to O₂ (0.1)/He gascould become 10:0.3. Then, while carefully reading the pirani gage 1442,the opening of the auxiliary valves 1441-1 and 1441-2 were adjusted andthey were opened to the extent until the inner pressure in the chamber1401 became 1×10⁻² Torr. After the inner pressure in the chamber 1401was stabilized, the main valve 1410 was gradually closed to narrow itsopening until the indication on the pirani gage 1442 became 0.1 Torr.

After confirming that the gas inflow and the inner pressure were stable,followed by turning on of the switch of the high frequency power source1443 and closing of the shutter 1405 (which was also the electrode), ahigh frequency power of 13.56 MHz was applied between the electrode 1403and the shutter 1405 to generate glow discharging in the chamber 1401 toprovide an input power of 10 W. The above conditions were maintained for3 hours to form a photoconductive layer constituted of an amorphousmaterial containing oxygen atoms. Thereafter, with the high frequencypower source 1443 turned off for intermission of the glow discharge, theoutflow valve 1427 was closed, and then under the pressure of 1 kg/cm²(reading on the outlet pressure gage 1439) of O₂ gas (purity: 99.999%)from the bomb 1414 through the valve 1434, the inflow valve 1424 and theoutflow valve 1429 were gradually opened to introduce O₂ gas into themass flow controller 1419, and the amount of O₂ gas was stabilized byadjustment of the mass flow controller 1419 to 1/10 of the flow amountof SiH₄ (10)/H₂ gas.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 3 W. After glowdischarge was continued for additional 10 minutes to form an upperbarrier layer to a thickness of 600 Å, the heater 1408 was turned off,with the high frequency power source 1443 being also turned off, thesubstrate was left to cool to 100° C., whereupon the outflow valves1426, 1429 and the inflow valves 1421, 1422, 1424 were closed, with themain valve 1410 being fully opened, thereby to make the inner pressurein the chamber 1401 to 10⁻⁵ Torr or less. Then, the main valve 1410 wasclosed and the inner pressure in the chamber 1401 was made atmosphericthrough the leak valve 1406, and the substrate having formed respectivelayers was taken out. In this case, the entire thickness of the layersformed was about 9μ. The thus prepared image forming member was placedin an experimental device for charging and light exposure, and coronacharging was effected at -5.5 KV for 0.2 sec., followed immediately byirradiation of a light image. The light image was irradiated through atransmission type test chart using a tungsten lamp as light source at adosage of 1.0 lux. sec.

Immediately thereafter, positive (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the image forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

EXAMPLE 2

A molybdenum substrate was set similarly to in Example 1, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁶ Torraccording to the same procedures as in Example 1. After the substratetemperature was maintained at 250° C., according to the same proceduresas in Example 1, the auxiliary valves 1441-1, 1441-2, 1441-3,subsequently the outflow valves 1426, 1427, 1429 and inflow valves 1421,1422, 1424 were fully opened thereby to effect sufficiently degassing ofthe mass flow controllers 1416, 1417, 1419 to vacuo. After closing ofthe auxiliary valves 1441-1, 1441-2, 1441-3 and the valves 1426, 1427,1429, 1421, 1422, 1424, the valve 1431 of the gas bomb 1411 containingSiH₄ (10)/H₂ gas (purity: 99.999%) and the valve 1432 of the gas bomb1412 containing O₂ (0.1)/He were opened to adjust the pressures at theoutlet pressure gages 1436, 1437, respectively, to 1 kg/cm², followed bygradual opening of the inflow valves 1421, 1422 to introduce the SiH₄(10)/H₂ gas and O₂ (0.1)/He gas into the mass flow controllers 1416 and1417, respectively. Subsequently, the outflow valves 1426 and 1427 weregradually opened, followed by gradual opening of the auxiliary valves1441-1 and 1441-2. The mass flow controllers 1416 and 1417 were adjustedthereby so that the flow amount ratio of SiH₄ (10)/H₂ gas to O₂ (0.1)/Hegas could become 10:0.3. Then, while carefully reading the pirani gage1442, the openings of the auxiliary valves 1441-1, 1441-2 were adjustedand they were opened to the extent until the inner pressure in thechamber 1401 became 1×10⁻² Torr. After the inner pressure in the chamber1401 was stabilized, the main valve 1410 was gradually closed to narrowits opening until the indication on the pirani gage 1441 became 0.1Torr. After confirming that the gas inflow and the inner pressure werestable, followed by turning on of the switch of the high frequency powersource 1443 and closing of the shutter 1405 (which is also theelectrode), a high frequency power of 13.56 MHz was applied between theelectrodes 1403 and 1405 to generate glow discharging in the chamber1401 to provide an input power of 10 W. Simultaneously with commencementof formation of the photoconductive layer on the substrate under theabove initial layer forming conditions, the setting value of flow amountat the mass flow controller 1417 was continuously increased andformation of the photoconductive layer was conducted by controlling thegas flow amount ratio of SiH₄ (10)/H.sub. 2 to O₂ (0.1)/He 5 hours aftercommencement of layer formation to 1:1.

After completion of formation of the photoconductive layer, with thehigh frequency power source 1443 turned off for intermission of the glowdischarge, the outflow valve 1427 was closed, and then under thepressure of 1 kg/cm² (reading on the outlet pressure gage 1439) of O₂gas from the bomb 1414 through the valve 1434, the inflow valve 1424 andthe outflow valve 1429 were gradually opened to introduce O₂ gas intothe mass flow controller 1419, followed by gradual opening of theauxiliary valve 1441-3 simultaneously with adjustment of the mass flowcontroller 1419 to stabilize the flow amount of O₂ gas to 1/10 of theflow amount of SiH₄ (10)/H₂ gas.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 3 W. After glowdischarge was continued for additional 15 minutes to form an upperbarrier layer, the heater 1408 was turned off, with the high frequencypower source 1443 being also turned off, the substrate was left to coolto 100° C., whereupon the outflow valves 1426, 1429 and the inflowvalves 1421, 1422, 1424 were closed, with the main valve 1410 beingfully opened, thereby to make the inner pressure in the chamber 1401 to10⁻⁵ Torr or less. Then, the main valve 1410 was closed and the innerpressure in the chamber 1401 was made atmospheric through the leak valve1406, and the substrate having formed respective layers was taken out.In this case, the entire thickness of the layers formed was about 15μ.Using this image forming member, image was formed on a copying paperunder the same conditions and according to the same procedures as inExample 1, whereby there was obtained a very clear image-quality.

EXAMPLE 3

A molybdenum substrate was set similarly to in Example 1, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁶ Torraccording to the same procedures as in Example 1. After the substratetemperature was maintained at 250° C., according to the same proceduresas in Example 1, the auxiliary valves 1441-1, 1441-2, 1441-3,subsequently the outflow valves 1426, 1427, 1429 and inflow valves 1421,1422, 1424 were fully opened thereby to effect sufficiently degassing ofthe mass flow controllers 1416, 1417, 1419 to vacuo. After closing ofthe auxiliary valves 1441-1, 1441-2, 1441-3 and the valves 1426, 1427,1421, 1422, the valve 1431 of the bomb 1411 containing SiH₄ (10)/H₂ gas(purity: 99.999%) and the valve 1432 of the bomb 1412 containing O₂(0.1)/He gas were opened to adjust the pressures at the outlet pressuregages 1436, 1437, respectively, to 1 kg/cm², followed by gradual openingof the inflow valves 1421, 1422 to introduce the SiH₄ (10)/H₂ gas andO.sub. 2 (0.1)/He gas into the mass flow controllers 1416 and 1417,respectively. Subsequently, the outflow valves 1426 and 1427 weregradually opened, followed by gradual opening of the auxiliary valves1441-1 and 1441-2. The inflow valves 1421 and 1422 were adjusted therebyso that the gas flow amount ratio of SiH₄ (10)/H₂ to O₂ (0.1)/He was10:0.3.

Then, while carefully reading the pirani gage 1442, the openings of theauxiliary valves 1441-1, 1441-2 were adjusted until they were opened tothe extent until the inner pressure in the chamber 1401 became 1×10⁻²Torr. After the inner pressure in the chamber 1401 was stabilized, themain valve 1410 was gradually closed to narrow its opening until theindication on the pirani gage 1441 became 0.1 Torr. After confirmingthat the gas inflow and the inner pressure were stable, followed byturning on of the switch of the high frequency power source 1443 andclosing of the shutter 1405 (which is also the electrode), a highfrequency power of 13.56 MHz was applied between the electrodes 1403 and1405 to generate glow discharging in the chamber 1401 to provide aninput power of 10 W. Simultaneously with commencement of formation ofthe photoconductive layer on the substrate under the above initial layerforming conditions, the setting value of flow amount at the mass flowcontroller 1417 was continuously increased and formation of thephotoconductive layer was conducted by controlling the flow amount ratioof SiH₄ (10)/H₂ gas to O₂ (0.1)/He gas 5 hours after commencement oflayer formation to 1:10.

After formation of the photoconductive layer, the heater 1408 was turnedoff, with the high frequency power source 1443 being also turned off,the substrate was left to cool to 100° C., whereupon the outflow valves1426, 1429 and the inflow valves 1421, 1422, 1424 were closed, with themain valve 1410 being fully opened, thereby to make the inner pressurein the chamber 1401 to 10⁻⁵ Torr or less. Then, the main valve 1410 wasclosed and the inner pressure in the chamber 1401 was made atmosphericthrough the leak valve 1406, and the substrate having formed thephotoconductive layer was taken out. In this case, the thickness of thelayer formed was about 15μ. Using this image forming member, images wereformed on a copying paper under the same conditions and according to thesame procedures as in Example 1, whereby there was obtained a very clearimage-quality.

EXAMPLE 4

A photoconductive layer was formed on a molybdenum substrate under thesame operational conditions as described in Example 3 except for thefollowing conditions. Namely, the bomb 1411 containing SiH₄ (10)/H₂ gaswas replaced with the bomb containing SiF₄ gas (purity: 99.999%), andthe bomb 1412 containing O₂ (0.1)/He gas with the bomb of argon gas(purity: 99.999%) containing 0.2 vol. % of oxygen [hereinafter abridgedas O₂ (0.2)/Ar]. The flow amount ratio of SiF₄ gas to O₂ (0.2)/Ar at theinitial state of deposition of the photoconductive layer was set at1:0.6, and said flow amount ratio was continuously increased aftercommencement of the layer formation until it was 1:18 at the completionof deposition of the photoconductive layer. Further, the input power forglow discharging was changed to 100 W. The layer thickness formed inthis case was about 18μ. The thus prepared image forming member wastested for image formation on a copying paper according to the sameprocedures as in Example 1, whereby very clear images were obtained.

EXAMPLE 5

A molybdenum substrate was set similarly to in Example 1, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁶ Torraccording to the same procedures as in Example 1. After the substratetemperature was maintained at 250° C., according to the same proceduresas in Example 1, the auxiliary valves 1441-1, 1441-2, 1441-3,subsequently the outflow valves 1426, 1427, 1428, 1429 and inflow valves1421, 1422, 1423, 1424 were fully opened thereby to effect sufficientlydegassing of the mass flow controllers 1416, 1417, 1418, 1419 to vacuo.

After closing of the auxiliary valves 1441-1, 1441-2, 1441-3 and thevalves 1426, 1427, 1428, 1429, 1421, 1422, 1423, 1424, the valve 1431 ofthe bomb 1411 containing SiH₄ (10)/H₂ gas (purity: 99.999%), the valve1432 f the bomb 1412 containing O₂ (0.1)/He gas, and the valve 1433 ofthe bomb 1413 containing B₂ H₆ gas (purity: 99.999%) diluted to 50 vol.ppm with H₂ [hereinafter abridged as B₂ H₆ (50)/H₂ ] were opened toadjust the pressures at the outlet pressure gages 1436, 1437, 1438,respectively, to 1 kg/cm², followed by gradual opening of the inflowvalves 1421, 1422, 1423 to introduce the SiH₄ (10)/H₂ gas, O₂ (0.1)/Hegas, and B₂ H₆ (50)/H₂ gas into the mass flow controllers 1416, 1417 and1418 respectively. Subsequently, the outflow valves 1426, 1427 and 1428were gradually opened, followed by gradual opening of the auxiliaryvalves 1441-1, 1441-2 and 1441-3. The mass flow controllers 1416, 1417and 1418 were adjusted thereby so that the flow amount ratio of SiH₄(10)/H₂ to O₂ (0.1)/He was 10:0.3, and the feed ratio of SiH₄ (10)/H₂ toB₂ H₆ (50)/H₂ was 50:1. Then, while carefully reading the pirani gage1442, the opening of the auxiliary valves 1441-1 and 1441-2 wereadjusted and they were opened to the extent until the inner pressure inthe chamber 1401 became 1×10⁻² Torr. After the inner pressure in thechamber 1401 was stabilized, the main valve 1410 was gradually closed tonarrow its opening until the indication on the pirani gage 1442 became0.1 Torr. After confirming that the gas inflow and the inner pressurewere stable, followed by turning on of the switch of the high frequencypower source 1443 and closing of the shutter 1405 (which was also theelectrode), a high frequency power of 13.56 MHz was applied between theelectrode 1403 and the shutter 1405 to generate glow discharging in thechamber 1401 to provide an input power of 10 W. The above conditionswere maintained for 3 hours to form a photoconductive layer. Thereafter,with the high frequency power source 1443 turned off for intermission ofthe glow discharge, the outflow valves 1427 and 1428 were closed, andthen under the pressure of 1 kg/cm² (reading on the outlet pressure gage1439) of O₂ gas (purity: 99.999%) from the bomb 1414 through the valve1434, the inflow valve 1424 and the outflow valve 1429 were graduallyopened to introduce O₂ gas into the mass flow controller 1419, and thensimultaneously with gradual opening of the auxiliary valve 1441-3 theamount of O₂ gas was stabilized by adjustment of the mass flowcontroller 1419 to 1/10 of the flow amount of SiH₄ (10)/H₂ gas.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 3 W. After glowdischarge was continued for additional 10 minutes to form an upperbarrier layer to a thickness of 600 Å, the heater 1408 was turned off,with the high frequency power source 1443 being also turned off, thesubstrate was left to cool to 100° C., whereupon the outflow valves1426, 1429 and the inflow valves 1421, 1422, 1423, 1424 were closed,with the main valve 1410 being fully opened, thereby to make the innerpressure in the chamber 1401 to 10⁻⁵ Torr or less. Then, the main valve1410 was closed and the inner pressure in the chamber 1401 was madeatmospheric through the leak valve 1406, and the substrate having formedrespective layers was taken out. In this case, the entire thickness ofthe layers was about 9μ. The thus prepared image forming member wasplaced in an experimental device for charging and light-exposure, andcorona charging was effected at -5.5 KV for 0.2 sec., followedimmediately by irradiation of a light image. The light image wasirradiated through a transmission type test chart using a tungsten lampas light source at a dosage of 1.0 lux. sec.

Immediately thereafter, positively (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the image forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

Next, the above image forming member was subjected to corona charging bymeans of a charging light-exposure experimental device at +6.0 KV for0.2 sec., followed immediately by image exposure to light at a dosage of0.8 lux. sec., and thereafter immediately (-) charged developer wascascaded on the surface of the member. Then, by copying on a copyingpaper and fixing, there was obtained a very clear image.

As apparently seen from the above result, in combination with theprevious result, the image forming member for electrophotographyobtained in this Example has the characteristics of a both-polarityimage forming member having no dependency on the charged polarity.

EXAMPLE 6

Using a device as shown in FIG. 14, an image forming member forelectrophotography was prepared according to the following procedures.

A molybdenum plate (substrate) 1409 of 10 cm square having a thicknessof 0.5 mm, which surface had been cleaned, was fixed firmly on a fixingmember 1403 disposed at a predetermined position in a deposition chamber1401. The target 1404 was formed by mounting a high purity graphite(99.999%) on a high purity polycrystalline silicon (99.999%). Thesubstrate 1409 was heated by a heater 1408 within the fixing member 1403with a precision of ±0.5° C. The temperature was measured directly atthe backside of the substrate by an alumel-chromel thermocouple. Then,after confirming that all the valves in the system were closed, the mainvalve 1410 was opened, and evacuation of the chamber 1401 was effectedto about 5×10⁻⁶ Torr (all the valves except for the main valve wereclosed after this operation).

Then, the auxiliary valves 1441-1, 1441-2, 1441-3, subsequently theoutflow valves 1426, 1427, 1429, 1430 were opened to effect degassingsufficiently in the mass flow controllers 1416, 1417, 1419, 1420 tovacuo. Thereafter, the outflow valves 1426, 1427, 1429, 1430 and theauxiliary valves 1441-1, 1441-2 and 1441-3 were closed. The valve 1435of the bomb 1415 containing argon gas (purity: 99.999%) was opened toadjust the pressure at the outlet pressure gage 1440 at 1 kg/cm²,whereupon the inflow valve 1425 was opened, followed by gradual openingof the outflow valve 1430 to introduce argon gas into the chamber 1401.Subsequently, the outflow valve 1430 was gradually open until theindication on the pirani gage 1442 became 5×10⁻⁴ Torr. After the flowamount was stabilized under this state, the main valve 1410 wasgradually closed to narrow its opening until the inner pressure in thechamber 1401 became 1×10⁻² Torr. After confirming that the mass flowcontroller 1420 was stabilized, with the shutter being closed, the highfrequency power source 1443 was turned on to input an alternate currentof 13.56 MHz, 100 W between the target 1404 and the fixing member 1403.A layer was formed, while taking matching so as to continue dischargingstably under the above conditions. Thus, discharging was continued forone minute to form as intermediate layer with a thickness of 100 Å.Thereafter, with the high frequency power source 1443 turned off forintermission of the glow discharge, the outflow valve 1430 was closed,with full opening of the main valve 1410 to draw out the gas in thechamber 1401 to vacuum of 5×10⁻⁶ Torr. Then, the input voltage at theheater 1408 was elevated and the input voltage was changed whiledetecting the temperature of the substrate, until it was stabilizedconstantly at 200° C. Following afterwards the procedures similar toExample 1 under the same conditions, a photoconductive layer was formed.The thus prepared image forming member was tested for image formation ona copying paper similarly to described in Example 1, whereby there wasobtained a very clear and sharp image quality.

EXAMPLE 7

A photoconductive layer was formed according to the same procedures andunder the same conditions as in Example 4, except that the O₂ (0.2)/Argas bomb 1412 was replaced with the bomb of He gas containing 0.2 vol. %of O₂ gas.

The thickness of the layer formed in this case was about 15μ. Using thisimage forming member, an image was formed on a copying paper similarlyto described in Example 1 to obtain a very clear image.

EXAMPLE 8

Using a device as shown in FIG. 14 placed in a clean room which had beencompletely shielded, an image forming member for electrophotography wasprepared according to the following procedures.

A molybdenum plate (substrate) 1409 of 10 cm square having a thicknessof 0.5 mm, which surface had been cleaned, was fixed firmly on a fixingmember 1403 disposed at a predetermined position in a glow dischargedeposition chamber 1401. The substrate 1409 was heated by a heater 1408within the fixing member 1403 with a precision of ±0.5° C. Thetemperature was measured directly at the backside of the substrate by analumel-chromel thermocouple. Then, after confirming that all the valvesin the system were closed, the main valve 1410 was fully opened, andevacuation of the chamber 1401 was effected to about 5×10⁻⁶ Torr.Thereafter, the input voltage for the heater 1408 was elevated byvarying the input voltage while detecting the substrate temperatureuntil the temperature was stabilized constantly at 250° C.

Then, the auxiliary valves 1441-1, 1441-2, 1441-3, subsequently theoutflow valves 1426, 1427, 1429 and the inflow valves 1421, 1422, 1424were opened fully to effect degassing sufficiently in the mass flowcontrollers 1416, 1417, 1419 to vacuo. After closing the auxiliaryvalves 1441-1, 1441-2, 1441-3 and the valves 1426, 1427, 1429, 1421,1422, 1424, the valve 1431 of the bomb 1411 containing SiH₄ (10)/H₂ gas(purity: 99.999%) and the valve 1434 of the bomb 1414 containing O₂ gas(purity: 99.999%) were respectively opened to adjust the pressures atthe outlet pressure gages 1436 and 1439, respectively, at 1 kg/cm²,whereupon the inflow valves 1421 and 1424 were gradually opened tointroduce SiH₄ (10)/H₂ gas and O₂ gas into the mass flow controllers1416 and 1419, respectively. Subsequently, the outflow valves 1426 and1429 were gradually opened, followed by opening of the auxiliary valves1441-1, 1441-3. The mass flow controllers 1416 and 1419 were adjustedthereby so that the gas flow amount ratio of SiH₄ (10)/H₂ gas to O₂could become 10:1. Then, while carefully reading the pirani gage 1442,the opening of the auxiliary valves 1441-1 and 1441-3 were adjusted andthey were opened to the extent until the inner pressure in the chamber1401 became 1×10⁻² Torr.

After the inner pressure in the chamber 1401 was stabilized, the mainvalve 1410 was gradually closed to narrow its opening until theindication of the pirani gage 1442 became 0.1 Torr. After confirmingthat the gas inflow and the inner pressure were stable, followed byclosing of the shutter 1405 (which was also the electrode), the switchof the high frequence power source 1443 was turned on to input a highfrequency power of 13.56 MHz was applied between the electrode 1403 andthe shutter 1405 to generate glow discharging in the chamber 1401 toprovide an input power of 3 W. The above conditions were maintained for10 minutes to form a lower barrier layer of 600 Å in thickness on themolybdenum substrate. Thereafter, with the high frequency power source1443 turned off for intermission of the glow discharge, the outflowvalve 1429 was closed, and then under the pressure of 1 kg/cm² (readingon the outlet pressure gage 1437) of O₂ (0.1)/He gas from the bomb 1412through the valve 1432, the inflow valve 1422 and the outflow valve 1427were gradually opened to introduce O₂ (0.1)/He gas into the mass flowcontroller 1417, and the amount of O₂ (0.1)/He gas was stabilized byadjustment of the mass flow controllers 1416, 1417 so that the ratio ofthe flow amount of SiH₄ (10)/H₂ gas to that of the O₂ (0.1)/He gas was1:1.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 10 W. Under the aboveconditions, a photoconductive layer began to be formed on the lowerbarrier layer and at the same time the setting value of flow amount atthe mass flow controller 1417 was continuously decreased over 3 hoursuntil the flow amount ratio of the SiH₄ (10)/H₂ gas to O₂ (0.1)/He gasafter 3 hours became 10:0.3. The layer formation was thus conducted for3 hours. Then, the heater 1408 was turned off, with the high frequencypower source 1443 being also turned off, the substrate was left to coolto 100° C. whereupon the outflow valves 1426, 1427 and the inflow valves1421, 1422, 1424 were closed, with the main valve 1410 being fullyopened, thereby to make the inner pressure in the chamber 1401 to 10⁻⁵Torr or less. Then, the main valve 1410 was closed and the innerpressure in the chamber 1401 was made atmospheric through the leak valve1406, and the substrate having formed respective layers was taken out.In this case, the entire thickness of the layers was about 9μ.

The thus prepared image forming member was placed in an experimentaldevice for charging and light-exposure, and corona charging was effectedat -5.5 KV for 0.2 sec., followed immediately by irradiation of a lightimage. The light image was irradiated through a transmission type testchart using a tungsten lamp as light source at a dosage of 1.0 lux. sec.

Immediately thereafter, positively (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the image forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

EXAMPLE 9

A molybdenum substrate was set similarly to in Example 8, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁶ Torraccording to the same procedures as in Example 8. After the substratetemperature was maintained at 250° C., according to the same proceduresas in Example 8, the auxiliary valves 1441-1, 1141-2, 1441-3,subsequently the outflow valves 1426, 1427 and inflow valves 1421, 1422were fully opened thereby to effect sufficiently degassing of the massflow controllers 1416, 1417 to vacuo. After closing of the auxiliaryvalves 1441-1, 1441-2, 1441-3 and the valves 1426, 1427, 1421, 1422, thevalve 1431 of the gas bomb 1411 containing SiH₄ (10)/H₂ gas and thevalve 1432 of the gas bomb 1412 containing O₂ (0.1)/He were opened toadjust the pressures at the outlet pressure gages 1436, 1437,respectively, to 1 kg/cm², followed by gradual opening of the inflowvalves 1421, 1422 to introduce the SiH₄ (10)/H₂ gas and O₂ (0.1)/He gasinto the mass flow controllers 1416 and 1417, respectively.Subsequently, the outflow valves 1426 and 1427 were gradually opened,followed by gradual opening of the auxiliary valves 1441-1 and 1441-2.The mass flow controllers 1416 and 1417 were adjusted thereby so thatthe gas flow amount ratio of SiH₄ (10)/H₂ to O₂ (0.1)/He was 1:10.

Then, while carefully reading the pirani gage 1442, the openings of theauxiliary valves 1441-1, 1441-2 were adjusted, and they were opened tothe extent until the inner pressure in the chamber 1401 became 1×10⁻²Torr. After the inner pressure in the chamber 1401 was stabilized, themain valve 1410 was gradually closed to narrow its opening until theindication on the pirani gage 1441 became 0.1 Torr. After confirmingthat the gas inflow and the inner pressure were stable, followed byclosing of the shutter 1405, the switch of the high frequency powersource 1443 was turned on to input a high frequency power of 13.56 MHzbetween the electrode 1403 and the shutter 1405 to generate glowdischarging in the chamber 1401 to provide an input power of 10 W.Simultaneously with commencement of formation of the photoconductivelayer on the substrate under the above initial layer forming conditions,the setting value of flow amount at the mass flow controller 1417 wascontinuously decreased and formation of the photoconductive layer wasconducted by controlling the gas flow amount ratio of SiH₄ (10)/H₂ to O₂(0.1)/He 5 hours after commencement of layer formation to 10:0.3.

After completion of formation of the photoconductive layer, the heater1408 was turned off, with the high frequency power source 1443 beingalso turned off, and the substrate was left to cool to 100° C.,whereupon the outflow valves 1426, 1427 and the inflow valves 1421, 1422were closed, with the main valve 1410 being fully opened, thereby tomake the inner pressure in the chamber 1401 to 10⁻⁵ Torr or less. Then,the main valve 1410 was closed and the inner pressure in the chamber1401 was made atmospheric through the leak valve 1406, and the substratehaving formed respective layers was taken out. In this case, the entirethickness of the layers formed was about 15μ. Using this image formingmember, image was formed on a copying paper under the same conditionsand according to the same procedures as in Example 8, whereby there wasobtained a very clear image.

EXAMPLE 10

After formation of a lower barrier layer and a photoconductive layer ona molybdenum substrate according to the same procedures and under thesame conditions as in Example 8, the high frequency power source 1443was turned off for intermission of glow discharge. Under this state, theoutflow valve 1427 was closed and then the outflow valve 1429 was openedagain, and the flow amount ratio of O₂ gas to SiH₄ (10)/H₂ wasstabilized to 1/10 by adjusting the mass flow controllers 1419 and 1416.Subsequently, the high frequency power source 1443 was turned on torecommence glow discharging. The input voltage was thereby adjusted to 3W, similarly as before.

Under these conditions, glow discharge was further maintained for 15minutes to form an upper barrier layer to a thickness of 900 Å, andthereafter the heater 1408 was turned off, with the high frequency powersource 1443 being also turned off, the substrate was left to cool to100° C., whereupon the outflow valves 1426, 1429 and the inflow valves1421, 1422, 1424 were closed, with the main valve 1410 being fullyopened, thereby to make the inner pressure in the chamber 1401 to 10⁻⁵Torr or less. Then, the main valve 1410 was closed and the innerpressure in the chamber 1401 was made atmospheric through the leak valve1406, and the substrate having formed respective layers was taken out.In this case, the entire thickness of the layers formed was about 9μ.Using this image forming member, image was formed on a copying paperunder the same conditions and according to the same procedures as inExample 8, whereby there was obtained a very clear image.

EXAMPLE 11

After formation of a photoconductive layer on a molybdenum substrateaccording to the same procedures and under the same conditions as inExample 9, the high frequency power source 1443 was turned off forintermission of glow discharge. Under this state, the outflow valve 1427was closed and then the outflow valve 1429 was opened again, and theflow amount ratio of O₂ gas to SiH₄ (10)/H₂ was stabilized to 1/10 byadjusting the mass flow controllers 1419 and 1416. Subsequently, thehigh frequency power source was turned on to recommence glowdischarging. The input voltage was thereby adjusted to 3 W, similarly asbefore.

Under these conditions, glow discharge was further maintained for 10minutes to form an upper barrier layer to a thickness of 900 Å, andthereafter the heater 1408 was turned off, with the high frequency powersource 1443 being also turned off, the substrate was left to cool to100° C., whereupon the outflow valves 1426, 1429 and the inflow valves1421, 1422, 1424 were closed, with the main valve 1410 being fullyopened, thereby to make the inner pressure in the chamber 1401 to 10⁻⁵Torr or less. Then, the main valve 1410 was closed and the innerpressure in the chamber 1401 was made atmospheric through the leak valve1406, and the substrate having formed respective layers was taken out.In this case, the entire thickness of the layers formed was about 15μ.Using this image forming member, image was formed on a copying paperunder the same conditions and according to the same procedures as inExample 8, whereby there was obtained a very clear image quality.

EXAMPLE 12

A molybdenum substrate was set similarly to in Example 8, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁶ Torraccording to the same procedures as in Example 8. After the substratetemperature was maintained at 250° C., according to the same proceduresas in Example 8, the auxiliary valves 1441-1, 1441-2, subsequently theoutflow valves 1426, 1427, and inflow valves 1421, 1422 were fullyopened thereby to effect sufficiently degassing of the mass flowcontrollers 1416, 1417 to vacuo. After closing of the auxiliary valves1441-1, 1441-2, and the valves 1426, 1427, 1421, 1422, the valve 1431 ofthe bomb 1411 containing SiH₄ (10)/H₂ gas and the valve 1432 of the bomb1412 containing O₂ (0.1)/He were opened to adjust the pressures at theoutlet pressure gages 1436, 1437, respectively, to 1 kg/cm², followed bygradual opening of the inflow valves 1421, 1422 to introduce the SiH₄(10)/H₂ gas and O₂ (0.1)/He gas into the mass flow controllers 1416 and1417, respectively. Subsequently, the outflow valves 1426 and 1427 weregradually opened, followed by gradual opening of the auxiliary valves1441-1 and 1441-2. The mass flow controllers 1416 and 1417 were adjustedthereby so that the gas flow amount ratio of SiH₄ (10)/H₂ to O₂ (0.1)/Hewas 1:10.

Then, while carefully reading the pirani gage 1442, the openings of theauxiliary valves 1441-1, 1441-2 were adjusted and they were opened tothe extent until the inner pressure in the chamber 1401 became 1×10⁻²Torr. After the inner pressure in the chamber 1401 was stabilized, themain valve 1410 was gradually closed to narrow its opening until theindication on the pirani gage 1442 became 0.3 Torr. After confirmingthat the gas inflow and the inner pressure were stable, followed byclosing of the shutter 1405, the switch of the high frequency powersource 1443 was turned on to input a high frequency power of 13.56 MHzbetween the electrode 1403 and the shutter 1405 to generate glowdischarging in the chamber 1401 to provide an input power of 10 W.Simultaneously with commencement of formation of the photoconductivelayer on the substrate under the above initial layer forming conditions,the setting value of flow amount at the mass flow controller 1417 wascontinuously decreased and formation of the photoconductive layer wasconducted by controlling the gas flow amount ratio of SiH₄ (10)/H₂ to O₂(0.1)/He 2.5 hours after commencement of layer formation to 10:0.3.Then, after said ratio had been maintained for 30 minutes, the settingvalue of flow amount at the mass flow controller 1417 was continuouslyincreased, as contrary to the previous operation, until the gas flowamount ratio of SiH₄ (10)/H₂ to O₂ (0.1)/He was adjusted to 1:10 for 2.5hours after commencement of increase of the flow amount.

After completion of formation of the photoconductive layer, the heater1408 was turned off, with the high frequency power source 1443 beingalso turned off, and the substrate was left to cool to 100° C.,whereupon the outflow valves 1426, 1427 and the inflow valves 1421, 1422were closed, with the main valve 1410 being fully opened, thereby tomake the inner pressure in the chamber 1401 to 10⁻⁵ Torr or less. Then,the main valve 1410 was closed and the inner pressure in the chamber1401 was made atmospheric through the leak valve 1406, and the substratehaving formed layers was taken out. In this case, the entire thicknessof the layers formed was about 17μ. Using this image forming member,image was formed on a copying paper under the same conditions andaccording to the same procedures as in Example 8, whereby there wasobtained a very clear image.

EXAMPLE 13

After formation of a lower barrier layer on a molybdenum substrateaccording to the same procedures and under the same conditions as inExample 8, the high frequency power source 1443 was turned off forintermission of glow discharge. Under this state, the outflow valve 1429was closed and thereafter the valve 1432 of the bomb 1412 containing O₂(0.1)/He gas and the valve 1433 of the bomb 1413 containing B₂ H₆ gas(purity: 99.999%) diluted to 50 vol. ppm with H₂ [hereinafter abridgedas B₂ H₆ (50)/H₂ ] were opened to adjust the pressures at the outletpressure gages 1437, 1438, respectively, to 1 kg/cm², followed bygradual opening of the inflow valves 1422, 1423 to introduce the O₂(0.1)/He gas and B₂ H₆ (50)/H₂ gas into the mass flow controllers, 1417,and 1418 respectively. Subsequently, the outflow valves 1427 and 1428were gradually opened, and the mass flow controllers 1416, 1417 and 1418were adjusted thereby so that the gas flow amount ratio of SiH₄ (10)/H₂to O₂ (0.1)/He was 1:10, and the flow amount ratio of SiH₄ (10)/H₂ to B₂to B₂ H₆ (50)/H₂ was 1:5. Then, while carefully reading the pirani gage1442, the opening of the auxiliary valves 1441-1 and 1441-2 wereadjusted and they were opened to the extent until the inner pressure inthe chamber 1401 became 1×10⁻² Torr. After the inner pressure in thechamber 1401 was stabilized, the main valve 1410 was gradually closed tonarrow its opening until the indication of the pirani gage 1442 become0.1 Torr.

After confirming that the gas feeding and the inner pressure werestable, the switch of the high frequency power source 1443 was turned onto input a high frequency power of 13.56 MHz to recommence glowdischarging in the chamber 1401 to provide an input power of 10 W.

Simultaneously with commencement of formation of the photoconductivelayer on the substrate under the above conditions, the setting value offlow amount at the mass flow controller 1417 was continuously decreasedand formation of the photoconductive layer was conducted by controllingthe gas flow amount ratio of SiH₄ (10)/H₂ to O₂ (0.1)/He 5 hours aftercommencement of layer formation to 10:0.3. After the photoconductivelayer was thus formed for 5 hours, the heater 1408 was turned off, withthe high frequency power source 1443 being also turned off, and thesubstrate was left to cool to 100° C., whereupon the outflow valves1426, 1427, 1428 and the inflow valves 1421, 1422, 1423, 1424 wereclosed, with the main valve 1410 being fully opened, thereby to make theinner pressure in the chamber 1401 to 10⁻⁵ Torr or less. Then, the mainvalve 1410 was closed and the inner pressure in the chamber 1401 wasmade atmospheric through the leak valve 1406, and the substrate havingformed respective layers was taken out. In this case, the entirethickness of the layers formed was about 15μ.

The thus prepared image forming member was placed in an experimentaldevice for charging and light-exposure, and corona charging was effectedat -5.5 KV for 0.2 sec., followed immediately by irradiation of a lightimage. The light image was irradiated through a transmission type testchart using a tungsten lamp as light source at a dosage of 1.0 lux. sec.

Immediately thereafter, positively (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the imaging forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

Next, the above image forming member was subjected to corona charging bymeans of a charging light-exposure experimental device at +6.0 KV for0.2 sec., followed immediately by image exposure to light at a dosage of1.0 lux. sec., and thereafter immediately (-) charged developer wascascaded on the surface of the member. Then, by copying on a copyingpaper and fixing, there was obtained a very clear image.

As apparently seen from the above result, in combination with theprevious result, the image forming member for electrophotographyobtained in this Example has the characteristics of a both-polarityimage forming member having no dependency on the charged polarity.

EXAMPLE 14

A photoconductive layer was formed on a molybdenum substrate under thesame operational conditions as described in Example 9 except for thefollowing conditions. Namely, the SiH₄ (10)/H₂ gas bomb 1411 wasreplaced with the bomb containing SiF₄ gas (purity: 99.999%), and thebomb 1412 containing O₂ (0.1)/He gas with the bomb of argon gas (purity:99.999%) containing 0.2 vol. % for oxygen [hereinafter abridged as O₂(0.2)/Ar]. The flow amount ratio of SiF₄ gas to O₂ (0.2)/Ar at theinitial state of deposition of the photoconductive layer was set at1:18, and the flow amount of O₂ (0.2)/Ar was continuously decreasedafter commencement of the layer formation so that the flow amount ratioof SiF₄ gas to O₂ (0.2)/Ar gas could become 1:0.6 at the completion ofdeposition of the photoconductive layer. Further, the input power forglow discharging was changed to 100 W. The layer thickness formed inthis case was about 18μ. The thus prepared image forming member wastested for image formation on a copying paper according to the sameprocedures as in Example 8, whereby a very clear image was obtained.

EXAMPLE 15

Using a device as shown in FIG. 14, an image forming member forelectrophotography was prepared according to the following procedures.

A molybdenum plate (substrate) 1409 of 10 cm square having a thicknessof 0.5 mm, which surface had been cleaned, was fixed firmly on a fixingmember 1403 disposed at a predetermined position in a deposition chamber1401. The target 1404 was formed by mounting a high purity graphite(99.999%) on a high purity polycrystalline silicon (99.999%). Thesubstrate 1409 was heated by a heater 1408 within the fixing member 1403with a precision of ±0.5° C. The temperature was measured directly atthe backside of the substrate by an alumel-chromel thermocouple. Then,after confirming that all the valves in the system were closed, the mainvalve 1410 was opened, and evacuation of the chamber 1401 was effectedto about 5×10⁻⁶ Torr (all the valves except for the main valve wereclosed during this operation).

Then, the auxiliary valves 1441-1, 1441-2, 1441-3, subsequently theoutflow valves 1426, 1427, 1429, 1430 were opened to effect degassingsufficiently in the mass flow controllers 1416, 1417, 1419, 1420 tovacuo. Thereafter, the outflow valves 1426, 1427, 1429, 1430 and theauxiliary valves 1441-1, 1441-2 and 1441-3 were closed. The valves 1435of the bomb 1415 containing argon gas (purity: 99.999%) was opened toadjust the pressure at the outlet pressure gage 1440 at 1 kg/cm²,whereupon the inflow valve 1425 was opened, followed by gradual openingof the outflow valve 1430 to introduce argon gas into the chamber 140./Subsequently the outflow valve 1430 was gradually opened until theindication on the pirani gage 1411 became 5×10⁻⁴ Torr. After the flowamount was stabilized under this state, the main valve 1410 wasgradually closed to narrow its opening until the inner pressure in thechamber 1401 became 1×10⁻² Torr. After confirming that the mass flowcontroller 1420 was stabilized, with the shutter being closed, the highfrequency power source 1443 was turned on to input an alternate currentof 13.56 MHz, 100 W between the target 1404 and the fixing member 1403.Formation of a layer was started, while taking matching so as tocontinue discharging stably under the above conditions. Thus,discharging was continued for one minute to form a lower barrier layerwith a thickness of 100 Å. Thereafter, with the high frequency powersource 1443 turned off for intermission of the glow discharge, theoutflow valve 1430 was closed, with full opening of the main valve 1410to draw out the gas in the chamber 1401 to vacuum of 5×10⁻⁶ Torr. Then,the input voltage at the heater 1408 was elevated and the input voltagewas changed while detecting the temperature of the substrate, until itwas stablized constantly at 200° C.

Following afterwards the procedures similar to Example 9 under the sameconditions, a photoconductive layer was formed. The thus prepared imageforming member was tested for image formation on a copying papersimilarly as described in Example 8, whereby there was obtained a veryclear and sharp image quality.

EXAMPLE 16

A photoconductive layer was formed on a molybdenum substrate accordingto the same procedures and under the same conditions as in Example 14,except that the bomb 1412 containing O₂ (0.2)/Ar gas was replaced withthe bomb of He gas containing 0.2 vol. % of O₂ gas.

The thickness of the layer formed in this case was about 15μ. Using thisimage forming member, an image was formed on a copying paper similarlyto described in Example 8 to obtain a very clear image.

EXAMPLE 17

Using a device as shown in FIG. 14 placed in a clean room which had beencompletely shielded, an image forming member for electrophotography wasprepared according to the following procedures.

A molybdenum plate (substrate) 1409 of 10 cm square having a thicknessof 0.5 mm, which surface had been cleaned, was fixed firmly on a fixingmember 1403 disposed at a predetermined position in a glow dischargedeposition chamber 1401. The substrate 1409 was heated by a heater 1408within the fixing member 1403 with a precision of ±0.5° C. Thetemperature was measured directly at the backside of the substrate by analumel-chromel thermocouple. Then, after confirming that all the valvesin the system were closed, the main valve 1410 was fully opened, andevacuation of the chamber 1401 was effected to about 5×10⁻⁶ Torr.Thereafter, the input voltage for the heater 1408 was elevated byvarying the input voltage while detecting the substrate temperatureuntil the temperature was stabilized constantly at 250° C.

Then, the auxiliary valves 1441-1, 1441-2, 1441-3, subsequently theoutflow valves 1426, 1427, 1429 and the inflow valves 1421, 1422, 1424were opened fully to effect degassing sufficiently in the mass flowcontrollers 1416, 1417, 1419 to vacuo. After closing the valves 1426,1427, 1429, 1421, 1424, the valve 1431 of the bomb 1411 containing SiH₄(10)/H₂ gas and the valve 1434 of the bomb 1414 containing O₂ gas(purity: 99.999%) were respectively opened to adjust the pressures atthe outlet pressure gages 1436 and 1439, respectively, at 1 kg/cm²,whereupon the inflow valves 1421 and 1424 were gradually opened tointroduce SiH₄ (10)/H₂ gas and O₂ gas into the mass flow controllers1416 and 1419, respectively. Subsequently, the outflow valves 1426 and1429 were gradually opened, followed by opening of the auxiliary valves1441-1, 1441-3. The mass flow controllers 1416 and 1419 were adjustedthereby so that the gas flow amount ratio of SiH₄ (10)/H₂ to O₂ was10:1. Then, while carefully reading the pirani gage 1442, the opening ofthe auxiliary valves 1441-1 and 1441-3 were adjusted and they wereopened to the extent until the inner pressure in the chamber 1401 became1×10⁻² Torr.

After the inner pressure in the chamber 1401 was stabilized, the mainvalve 1410 was gradually closed to narrow its opening until theindication on the pirani gage 1442 became 0.1 Torr. After confirmingthat the gas inflow and the inner pressure were stable, followed byclosing of the shutter 1405, the switch of the high frequency powersource 1443 was turned on to input a high frequency power of 13.56 MHzbetween the electrode 1403 and the shutter 1405 to generate glowdischarging in the chamber 1401 to provide an input power of 3 W. Theabove conditions were maintained for 10 minutes to form lower layerregion which is a part of a photoconductive layer to a thickness of 600Å. Thereafter, with the high frequency power source 1443 turned off forintermission of the glow discharge, the outflow valve 1429 was closed,and then under the pressure of 1 kg/cm² (reading on the outlet pressuregage 1437) through the valve 1422 of the bomb 1412 containing O₂(0.1)/He gas, the inflow valve 1422, and the outflow valve 1427 weregradually opened to introduce O₂ (0.1)/He gas into the mass controller1417, and the flow amount ratio of O₂ (0.1)/He gas to SiH₄ (10)/H₂ wasadjusted by the mass flow controllers 1416 and 1417 so that the gas flowamount ratio of O₂ (0.1)/He to SiH₄ (10)/H₂ was 0.3:10.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 10 W.

After an intermediate layer region constituting a part of thephotoconductive layer was formed under the above conditions for 5 hours,the high frequency power source 1443 was turned off for intermission ofglow discharge. Under this state, the outflow valve 1427 was closed,followed by reopening of the outflow valve 1429, and the flow amount ofthe O₂ gas was stabilized to 1/10 based on the flow amount of SiH₄(10)/H₂ gas by adjustment of the mass flow controllers 1419, 1416.Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 3 W, similarly asbefore.

After glow discharging was maintained for 15 minutes to form an upperlayer region constituting a part of the photoconductive layer to athickness of 900 Å, the heater 1408 was turned off, with the highfrequency power source 1443 being also turned off, the substrate wasleft to cool to 100° C., whereupon the outflow valves 1426, 1429 and theinflow valves 1421, 1422, 1424 was closed, with the main valve 1410being fully opened, thereby to make the inner pressure in the chamber1401 to 10⁻⁵ Torr or less. Then, the main valve 1410 was closed and theinner pressure in the chamber 1401 was made atmospheric through the leakvalve 1406, and the substrate having formed respective layers was takenout. In this case, the entire thickness of the layers was about 15μ.

The thus prepared image forming member was placed in an experimentaldevice for charging and light-exposure, and corona charging was effectedat -5.5 KV for 0.2 sec., followed immediately by irradiation of a lightimage. The light image was irradiated through a transmission type testchart using a tungsten lamp as light source at a dosage of 1.0 lux. sec.

Immediately thereafter, positively (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the image forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

EXAMPLE 18

A molybdenum substrate was set similarly as in Example 17, followed byevacuation of the glow discharge deposition chamber 1401 to 5×10⁻⁵ Torraccording to the same procedures as in Example 17. According to the sameprocedures as in Example 17, the auxiliary valves 1441-1, 1441-2,1441-3, subsequently the outflow valves 1426, 1427, 1429, 1430 andinflow valves 1421, 1422, 1424, 1425 were fully opened thereby to effectsufficiently degassing of the mass flow controllers 1416, 1417, 1419,1420 to vacuo. After closing of the auxiliary valves 1441-1, 1441-2,1441-3 and the valves 1426, 1427, 1429, 1430, 1421, 1422, 1424, 1425,the valve 1435 of the bomb 1415 containing the argon gas (purity:99.999%) was opened to adjust the pressure at the outlet pressure gage1440 to 1 kg/cm², followed by opening of the inflow valve 1425 and thengradual opening of the outflow valve 1430 to introduce argon gas intothe chamber 1401. The outflow valve 1430 was gradually opened until theindication on the pirani gage 1411 became 5×10⁻⁴ Torr. After the flowamount was stabilized under this state, the main valve 1410 wasgradually closed to narrow its opening until the inner pressure in thechamber became 1×10⁻² Torr. The shutter 1405 was opened, and confirmingthat the mass flow controller 1420 was stabilized, the high frequencypower source 1443 was turned on to input an alternate current power of13.56 MHz, 100 W between the target 1404, which had a high puritygraphite wafer (purity:

99.999%) mounted on a high purity polycrystalline silicon wafer (purity:99.999%) and the fixing member 1403. Under these conditions, a layer wasformed while taking matching so as to continue stable discharging.Discharging was thus continued for one minute to form a lower barrierlayer with a thickness of 100 Å. The high frequency power source wasthereafter turned off for intermission of discharging. Subsequently, theoutflow valve 1430, the shutter 1405 were closed, with full opening ofthe main valve, 1410 to degas the chamber 1401 to 5×10⁻⁶. Then, theinput voltage at the heater 1408 was elevated, while detecting thesubstrate temperature, until it was stabilized constantly at 200° C.Following afterwards the procedures under the same conditions as inExample 17, a photoconductive layer was formed. The thus prepared imageforming member was used for image formation on a copying paper accordingto the same procedures and under the same conditions as in Example 17,whereby there was obtained a very clear and sharp image quality.

EXAMPLE 19

After formation of a lower layer region constituting a part of thephotoconductive layer on a molybdenum substrate according to the sameprocedures and under the same conditions as in Example 17, the highfrequency power source 1443 was turned off for intermission of glowdischarge. Under this state, the outflow valve 1429 was closed andthereafter the valve 1432 of the bomb 1412 containing O₂ (0.1)/He gasand the valve 1433 of the bomb 1413 containing B₂ H₆ (50)/H₂ gas wereopened to adjust the pressures at the outlet pressure gages 1437, 1438to 1 kg/cm², respectively followed by gradual opening of the inflowvalves 1422, 1423, to introduce O₂ (0.1)/He gas and B₂ H₆ (50)/H₂ gasinto the mass flow controllers 1417 and 1418, respectively.Subsequently, outflow valves 1427 and 1428 were gradually opened, andthe mass flow controllers 1416, 1417 and 1418 were controlled so thatthe ratio of the flow amount of SiH₄ (10)/H₂ to that of O₂ (0.1)/He was10:0.3 and the ratio of the flow amount of SiH₄ (10)/H₂ to that of B₂ H₆(50)/H₂ gas was 50:1. Then, while carefully reading the pirani gage1442, the opening of the auxiliary valves 1441-1 and 1441-2 were againadjusted and they were opened to the extent until the inner pressure inthe chamber 1401 became 1×10⁻² Torr. After the inner pressure in thechamber 1401 was stabilized, the main valve 1410 was again adjusted tonarrow its opening until the indication on the pirani gage 1442 became0.1 Torr.

After confirming that the gas inflow and the inner pressure werestabilized, the switch of the high frequency power source 1443 wasturned on again to input a high frequency power of 13.56 MHz torecommence glow discharging in the chamber 1401 to provide an inputpower of 10 W. The above conditions were maintained for 5 hours to forman intermediate layer region which was a part of a photoconductivelayer. Thereafter, with the high frequency power source 1443 turned offfor intermission of the glow discharge, the outflow valves 1427 and 1428were closed, and then the outflow valve 1429 was opened again and theratio of the flow amount of O₂ gas to SiH₄ (10)/H₂ gas was stabilized bycontrolling of the mass flow controllers 1419, 1416 to 1/10.

Subsequently, the high frequency power source 1443 was turned on againto recommence glow discharge. The input power was 3 W similarly to information of the lower layer region. After glow discharge was continuedfor additional 15 minutes to form an upper layer region which was a partof a photoconductive layer to a thickness of 900 Å, the heater 1408 wasturned off, with the high frequency power source 1443 being also turnedoff, the substrate was left to cool to 100° C., whereupon the outflowvalves 1426, 1427, 1428 and the inflow valves 1421, 1422, 1423, 1424were closed, with the main valve 1410 being fully opened, thereby tomake the inner pressure in the chamber 1401 to 10⁻⁵ Torr or less. Then,the main valve 1410 was closed and the inner pressure in the chamber1401 was made atmospheric through the leak valve 1406, and the substratehaving formed respective layers was taken out. In this case, the entirethickness of the layers was about 15μ.

The thus prepared image forming member was placed in an experimentaldevice for charging and light-exposure, and corona charging was effectedat -5.5 KV for 0.2 sec., followed immediately by irradiation of a lightimage. The light image was irradiated through a transmission type testchart using a tungsten lamp as light source at a dosage of 1.0 lux. sec.

Immediately thereafter, positively (+) charged developers (containingtoner and carrier) were cascaded on the surface of the image formingmember to obtain a good toner image on the image forming member. Whenthe toner image on the image forming member was copied on a copyingpaper by corona charging at -5.0 KV, there was obtained a clear image ofhigh density which was excellent in resolution as well as gradationreproducibility.

Next, the above image forming member was subjected to corona charging bymeans of a charging light-exposure experimental device at +6.0 KV for0.2 sec., followed immediately by image exposure to light at a dosage of1.0 lux. sec., and thereafter immediately (-) charged developer wascascaded on the surface of the member. Then, by copying on a copyingpaper and fixing, there was obtained a very clear image.

As apparently seen from the above result, in combination with theprevious result, the image forming member for electrophotographyobtained in this Example has the characteristics of a both-polarityimage forming member having no dependency on the charged polarity.

EXAMPLE 20

The bomb 1411 containing SiH₄ (10)/H₂ gas was previously replaced withthe bomb containing SiF₄ gas (purity:99.999%), and a lower barrier layerwas formed on a molybdenum substrate according to the same proceduresand under the same conditions as in Example 18. Then, with the highfrequency power source 1443 turned off for intermission of glowdischarge, the outflow valves 1430 and the shutter 1405 were closed,followed by full opening of the main valve 1410, to degas the chamber1401 to 5×10⁻⁶ Torr. The input voltage at the heater 1408 was thereafterelevated, while detecting the substrate temperature, until it wasstabilized constantly at 200° C. Then, with the shutter 1405 closed,SiF₄ gas and O₂ gas were used by setting their flow amount ratio at 1:1in forming the lower layer region and the upper layer region, while SiF₄gas and O₂ (0.1)/He gas were used by setting their flow amount ratio at2:1 in formation of the intermediate layer region, and the input powerfor glow discharge was 100 W. Under otherwise the same conditions as inExample 17, a photoconductive layer was formed.

After formation of the photoconductive layer, with the heater 1408turned off, the outflow valves 1426, 1428 were closed and the shutter1405 was opened again. When the substrate temperature was cooled to 80°C., the upper barrier layer was formed similarly under the sameconditions as in formation of the lower barrier layer.

After forming, on the substrate, the lower barrier layer, thephotoconductive layer and the upper barrier layer as described, the highfrequency power source 1443 was turned off, and the outflow valve 1430and the inflow valves 1421, 1422, 1425 were closed, with the main valve1410 being fully opened, thereby to make the inner pressure in thechamber 1401 to 10⁻⁵ Torr or less. Then, the main valve 1410 was closedand the inner pressure in the chamber 1401 was made atmospheric throughthe leak valve 1406, and the substrate having formed respective layerswas taken out. In this case, the entire thickness of the layers formedwas about 15μ. Using this image forming member, image was formed on acopying paper under the same conditions and according to the sameprocedures as in Example 17, whereby there was obtained a very clearimage.

What is claimed is:
 1. A photoconductive member, comprising a support for a photoconductive member and an amorphous layer which comprises silicon atoms as matrix containing at least one of hydrogen atom and halogen atom and exhibits photoconductivity, said amorphous layer having a layer region containing oxygen atom in at least a part thereof, the content of the oxygen atoms in said layer region being distributed unevenly in the direction of the thickness of said layer.
 2. A photoconductive member according to claim 1, wherein the layer region has a peak of the content of oxygen atoms distributed in the thickness direction of said layer.
 3. A photoconductive member according to claim 1, wherein the distribution profile of the content of oxygen atoms within said layer region in the layer thickness direction has the maximum value of distribution C_(max) on the side of the surface of the amorphous layer opposite to the side of said support.
 4. A photoconductive member according to claim 3, wherein the maximum value of distribution C_(max) is 0.3 to 67 atomic %.
 5. A photoconductive member according to claim 3, wherein the maximum value of distribution C_(max) is 0.3 to 67 atomic % and the total content of oxygen atoms in the layer region is 0.05 to 30 atomic %.
 6. A photoconductive member according to claim 1, wherein the distribution profile of the content of oxygen atoms within the layer region in the layer thickness direction has the maximum value of distribution C_(max) on the side of the support.
 7. A photoconductive member according to claim 6, wherein the maximum value of distribution C_(max) is 0.3 to 67 atomic %.
 8. A photoconductive member according to claim 6, wherein the maximum value of distribution C_(max) is 0.3 to 67 atomic % and the total content of oxygen atoms in the layer region is 0.05 to 30 atomic %.
 9. A photoconductive member according to claim 1, wherein the amorphous layer comprises a lower layer region in which the content of oxygen atoms is distributed substantially uniformly in the layer thickness direction at a distribution content of C₁, an upper layer region in which the content of oxygen atoms is distributed substantially uniformly in the layer thickness direction at a distribution content of C₂ and an intermediate layer region sandwiched between both of said layers, in which the content of oxygen atoms is distributed substantially uniformly in the layer thickness direction at a distribution content of C₃, the values of C₁ and C₂ being respectively greater than the value of C₃.
 10. A photoconductive member according to claim 9, wherein values of the distribution contents C₁ and C₂ range from 11 to 66 atomic %, and a value of the distribution content C₃ from 0.01 to 10 atomic %.
 11. A photoconductive member according to claim 9, wherein the total content of oxygen atoms is 0.05 to 30 atomic %, and values of the distribution contents C₁ and C₂ range from 11 to 66 atomic %, and a value of the distribution content C₃ from 0.01 to 10 atomic %.
 12. A photoconductive member according to claim 1, wherein the amorphous layer contains an impurity which controlls the electric conduction type.
 13. A photoconductive member according to claim 12, wherein the impurity is a p-type impurity.
 14. A photoconductive member according to claim 13, wherein the p-type impurity is an element in the group III A of the periodic table.
 15. A photoconductive member according to claim 14, wherein the element is selected from the group consisting of B, Al, Ga, In and Tl.
 16. A photoconductive member according to claim 13, wherein the content of the p-type impurity is 3×10⁻² atomic % or less.
 17. A photoconductive member according to claim 12, wherein the impurity is a n-type impurity.
 18. A photoconductive member according to claim 17, wherein the n-type impurity is an element in the group V A of the periodic table.
 19. A photoconductive member according to claim 18, wherein the element is selected from the group consisting of N, P, As, Sb and Bi.
 20. A photoconductive member according to claim 1, wherein the amorphous layer has a thickness of 3 to 100μ.
 21. A photoconductive member according to claim 1, wherein there is further provided an intermediate layer between the support and the amorphous layer.
 22. A photoconductive member according to claim 21, wherein the intermediate layer is a barrier layer.
 23. A photoconductive member according to claim 21, wherein the intermediate layer comprises an amorphous material comprising silicon atoms as matrix and at least one atom selected from the group consisting of carbon atom, nitrogen atom and oxygen atom as constituent elements.
 24. A photoconductive member according to claim 23, wherein the amorphous material further contains at least one of hydrogen atom and halogen atom as constituent elements.
 25. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula Si_(a) C_(1-a) wherein a is 0.1 to 0.4.
 26. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(b) C_(1-b))_(c) H_(1-c) wherein b is 0.1 to 0.5 and c is 0.6 to 0.99.
 27. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(d) C_(1-d))_(e) X_(1-e) wherein X represents a halogen atom, d is 0.1 to 0.47 and e is 0.8 to 0.99.
 28. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(f) C_(1-f))_(g) (H+X)_(1-g) wherein X represents a halogen atom, f is 0.1 to 0.47 and g is 0.8 to 0.99.
 29. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula Si_(h) N_(1-h) wherein h is 0.43 to 0.6.
 30. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(i) N_(1-i))_(j) H_(1-j) wherein i is 0.43 to 0.6 and j is 0.65 to 0.98.
 31. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(k) N_(1-k))_(l) X_(1-l) wherein X represents a halogen atom, k is 0.43 to 0.60 and l is 0.8 to 0.99.
 32. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(m) N_(1-m))_(n) (H+X)_(1-n) wherein X represents a halogen atom, m is 0.43 to 0.60 and n is 0.8 to 0.99.
 33. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula Si_(o) O_(1-o) wherein o is 0.33 to 0.40.
 34. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(p) O_(1-p))_(q) H_(1-q) wherein p is 0.33 to 0.40 and q is 0.65 to 0.98.
 35. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(r) O_(1-r))_(s) X_(1-s) wherein X represents a halogen atom, r is 0.33 to 0.40 and s is 0.80 to 0.99.
 36. A photoconductive member according to claim 23, wherein the amorphous material is represented by the formula (Si_(t) O_(1-t))_(u) (H+X)_(1-u) wherein X represents a halogen atom, t is 0.33 to 0.40 and u is 0.80 to 0.99.
 37. A photoconductive member according to claim 21, wherein the intermediate layer is constituted of an electrically insulating metal oxide.
 38. A photoconductive member according to claim 21, wherein the intermediate layer has a thickness of 30 to 1000 Å.
 39. A photoconductive member according to claim 1, wherein there is further provided an upper layer on the amorphous layer.
 40. A photoconductive member according to claim 39, wherein the upper layer is a barrier layer.
 41. A photoconductive member according to claim 39, wherein the upper layer comprises an amorphous material comprising silicon atoms as matrix and at least one atom selected from the group consisting of carbon atom, nitrogen atom and oxygen atom as constituent elements.
 42. A photoconductive member according to claim 41, wherein the amorphous material further contains at least one of hydrogen atom and halogen atom as constituent elements.
 43. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula Si_(a) C_(1-a) wherein a is 0.1 to 0.4.
 44. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(b) C_(1-b))_(c) H_(1-c) wherein b is 0.1 to 0.5 and c is 0.6 to 0.99.
 45. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(d) C_(1-d))_(e) X_(1-e) wherein X represents a halogen atom, d is 0.1 to 0.47 and e is 0.8 to 0.99.
 46. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(f) C_(1-f))_(g) (H+X)_(1-g) wherein X represents a halogen atom, f is 0.1 to 0.47 and g is 0.8 to 0.99.
 47. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula Si_(h) N_(1-h) wherein h is 0.43 to 0.6.
 48. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(i) N_(1-i))_(j) H_(1-j) wherein i is 0.43 to 0.6 and j is 0.65 to 0.98.
 49. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(k) N_(1-k))_(l) X_(1-l) wherein X represents a halogen atom, k is 0.43 to 0.60 and l is 0.8 to 0.99.
 50. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(m) N_(1-m))_(n) (H+X)_(1-n) wherein X represents a halogen atom, m is 0.43 to 0.60 and n is 0.8 to 0.99.
 51. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula Si_(o) O₁₋₀ wherein o is 0.33 to 0.40.
 52. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(p) O_(1-p))_(q) H_(1-q) wherein p is 0.33 to 0.40 and Q is 0.65 to 0.98.
 53. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(r) O_(1-r))_(s) X_(1-s) wherein X represents a halogen atom, r is 0.33 to 0.40 and s is 0.80 to 0.99.
 54. A photoconductive member according to claim 41, wherein the amorphous material is represented by the formula (Si_(t) O_(1-t))_(u) (H+X)_(1-u) wherein X represents a halogen atom, t is 0.33 to 0.40 and u is 0.80 to 0.99.
 55. A photoconductive member according to claim 39, wherein the upper layer is constituted of an electrically insulating metal oxide.
 56. A photoconductive member according to claim 39, wherein the upper layer has a thickness of 30 Å to 5μ.
 57. A photoconductive member according to claim 1, wherein the content of hydrogen atom in the amorphous layer is 1 to 40 atomic %.
 58. A photoconductive member according to claim 1, wherein the content of halogen atom in the amorphous layer is 1 to 40 atomic %.
 59. A photoconductive member according to claim 1, wherein both hydrogen atom and halogen atom are contained in the amorphous layer.
 60. A photoconductive member according to claim 59, wherein the sum of contents of hydrogen atom and halogen atom is 1 to 40 atomic %.
 61. A photoconductive member according to claim 60, wherein the content of hydrogen atoms is 19 atomic % or less.
 62. A photoconductive member according to claim 1, wherein the content of oxygen atom in the layer region is 0.05 to 30 atomic %.
 63. A photoconductive member, comprising a support for a photoconductive member and an amorphous layer which comprises silicon atoms as matrix and exhibits photoconductivity, said amorphous layer containing oxygen atoms and the distribution profile of the content of oxygen atoms being uneven in the direction of the layer thickness and having a maximum value C_(max).
 64. A photoconductive member according to claim 63, wherein the content of oxygen atom in the amorphous layer is 0.05 to 30 atomic %.
 65. A photoconductive member according to claim 63, wherein the amorphous layer further contains at least one atom selected from the group consisting of hydrogen atom and halogen atom as constituent elements.
 66. A photoconductive member according to claim 63, wherein the maximum value C_(max) in the content distribution of oxygen atom is 0.3 to 67 atomic %.
 67. A photoconductive member according to claim 1 or claim 63, wherein there is at least one portion in which the content distribution of oxygen atom is continuously decreased.
 68. A photoconductive member according to claim 63, wherein the amorphous layer is constituted of a lower layer region in which the content of oxygen atom is distributed substantially uniformly in the layer thickness direction at a distribution content of C₁, an upper layer region in which the content of oxygen atom is distributed substantially uniformly in the layer thickness direction at a distribution content of C₂ and an intermediate layer region sandwiched between both of said layers, in which the content of oxygen atom is distributed substantially uniformly in the layer thickness direction at a distribution content of C₃, the values of C₁ and C₂ being respectively greater than the value of C₃.
 69. A photoconductive member according to claim 9 or claim 68, wherein C₁ and C₂ are substantially equal.
 70. A photoconductive member according to claim 9 or claim 68, wherein C₁ and C₂ are different.
 71. A photoconductive member according to claim 68, wherein the amorphous layer contains an impurity which controls the electric conduction type.
 72. A photoconductive member according to claim 68, wherein the amorphous layer has a thickness of 3 to 100 microns.
 73. A photoconductive member according to claim 68, wherein there is further provided an intermediate layer between the support and the amorphous layer.
 74. A photoconductive member according to claim 68, wherein there is further provided an upper layer on the amorphous layer. 